Freescale-PC PCI express connector.

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This section is essentially created to help all PowerQUICC Processor users ranging from customers to designers to help provide the best solution to the most frequently encountered questions related to PowerQUICC Processor products. Feel free to browse through the various product FAQs to get answers to most commonly encountered questions on topics like DDR3, Ethernet (eTSEC), Booting, USB, Hardware Spec/Reference Manual and more. Drop a comment or two on how we can keep building these pages. Also, feel free to give your suggestions on what you feel should be added to the FAQs or to the FAQ section as a whole. We intend our Community to grow while mutually helping each other and by reducing design times by providing hands-on solution to tricky problems and questions.                                                                                                                                                                        MPC8306/MPC8306S FAQs MPC8306/MPC8306S Clocking Specific FAQs MPC8306/MPC8306S Hardware Specifications/Reference Manual Specific FAQs MPC8306/MPC8306S QUICC Engine Specific FAQs MPC8308 FAQs MPC8308 Clocking Specific FAQs MPC8308 DDR Specific FAQs MPC8308 PCIe Specific FAQs MPC8360 FAQs MPC8360 Clocking Specific FAQs MPC8360 DDR Specific FAQs MPC8535 FAQs MPC8535 Clocking Specific FAQs MPC8535 DDR Specific FAQs MPC8535 eSDHC Specific FAQs MPC8535 Hardware Specifications/Reference Manual Specific FAQs MPC8536 FAQs MPC8536 Clocking Specific FAQs MPC8536 DDR Specific FAQs MPC8536 eSDHC Specific FAQs MPC8536 Hardware Specifications/Reference Manual Specific FAQs MPC8541 FAQs MPC8541 Clocking Specific FAQs MPC8541 DDR Specific FAQs MPC8541 eSDHC Specific FAQs MPC8541 Ethernet (eTSEC) Specific FAQs MPC8541 Hardware Specifications/Reference Manual Specific FAQs MPC8541 PCIe Specific FAQs MPC8541 Power Management Specific FAQs MPC8543 FAQs MPC8543/MPC8545/MPC8547/MPC8548 GPIO Specific FAQs MPC8543/MPC8545/MPC8547/MPC8548 Hardware Specifications/Reference Manual Specific FAQs MPC8567/MPC8568 FAQs MPC8567/MPC8568 Hardware Specifications/Reference Manual Specific FAQs

For MPC8568, local bus has pin LAD [0:31] and LA [27:31]. LAD [0:31] is named as Muxed Data/ Address bus while LA [27:31] as address bus. Can LAD [27:31] be used as address bus in muxed mode using LALE signal? Yes, you can mux LAD [0:26] and LA [27:31] signals. For MPC8568, should LA [27:31] be always used as five least-significant address bits for addressing any device on local bus? LAD[0:31] works in most cases, but you need to be careful in the bursting case since LAD is latched once and fixed, while LA[27:31] increments during the burst. So we recommend LA [27:31] since it always works. I am using a single 20-A switching supply for both VDD_CA and VDD_CB, and we are considering the same power circuit for the MPC8568 CPU version. Since the MPC8568 is single core, what would be the effect of the 1.1V supply still connected to the VDD_CB pins of the MPC8568? TVDD_CB pins can be connected to MPC8568, but for minimum power consumption it is recommended to leave these pins not connected. Exact amount of additional power consumption if these pins are connected for MPC8568 is not defined, but it can be as much as maximum power consumption of an additional core. I would like to vary the core frequency up to the lowest possible value which is 800MHz for MPC8568 (according to the reference manual) via Software. What are the recommended values for lowest possible core frequency and lowest platform frequency? Recommended value for lowest possible core frequency is 667MHz and that for lowest platform frequency is 600MHz.

Does this output signal really need the pull up? Yes, IRQ_REQ output signal requires 2-10K ohm pull-up According to the section 20.10 of 8548EEC, SD_REF_CLK/SD_REF_CLK_B must be connected to GND if not used. Is this still required even when they have internal 50 ohm termination to GND? This note is per specfication. Yes, the SD_REF_CLK/_B are 50ohm terminated to ground. They are also AC coupled to the inputs of a differential amplifier. If they are not used and unconnected, we don't want them responding to any differential noise that might be present in the system, hence drawing unwanted current. Thus we recommend tying them to ground so that the inputs cannot respond to any differential noise. What is the pin compatibility difference between MPC8543 and MPC8548? MPC8543 and MPC8548 are built on same die and are pin compatible, only reduced functionality in MPC8543E.

Can the 8543 support the 16bit FIFO by combining the eTSEC1 pins with the GPIO pins that would otherwise be assigned to eTSEC2 in MPC8548? It is recommended for the unused I/O pins (such as the MECC [0:7]) to be pull down to GND via a 10k resistor. 8543 can, in fact, operate in 16-bit FIFO mode on eTSEC1. The key is to differentiate "signal functionality" from "logic resources." 8543 offers the logic for eTSEC1 and eTSEC3, but all the same signals are still there (including the signals otherwise used for eTSEC2). You'll notice that the references you note (T14-129, T14-173, Section C.2) all clearly make reference to "eTSEC2 signals". According to first bullet in section C.2 - "What signal functionality is NOT included in 8543: - eTSEC2 controller signals. Exceptions to this are when a) the signals are used as GPIO signals, or b) the signals are used to accommodate eTSEC1 in 16-bit FIFO mode." What will the value of GPOUT[0:7] be when they are disabled by GPIOCR? all 0? All 1? or all Hi-Z? GPOUT[0:7] pins are tristated if they are not enabled.

I would like to know if output signals of blocks which are not clocked during sleep mode are driven or not. For example, are eTSEC2 RGMII signals driven during sleep mode? Yes, they would be driven but there would be no activity on them. Please note that this is for "sleep" mode NOT "deep sleep" MPC8541 supports “Wake on LAN” from the Deep Sleep. If TSEC operates via SGMII it needs for SVDD,XVDD, SVDD2,VDD2, SDAVDD and SDAVDD2 (SGMII power). All these powers are switchable in the Deep Sleep. Can we leave these rails powered in the Deep Sleep and expect that the MPC8541 will support “Wake on LAN” via SGMII? Serdes is powered down during deep sleep, so Wake up on LAN is not supported for Deep Sleep in SGMII mode. Wake on LAN is supported for RGMII. Please note only eTSEC1 supports this feature. (Assuming eSTEC1 and eTSEC2 as the nomenclature) Are there any pull-downs for signals POWER_EN and ASLEEP on the MPC8541 board? Is BVDD switched off using POWER_EN? LOE has pull down via 4.7k ohms resistor as POR config. LWE has neither pull-up nor pull-down. Yes, BVdd is switched off using POWER_EN.

Does the PCIe controller go to D3 hot state automatically if the user does not configure any registers? Should the external device be in D3 hot state explicitly before MPC8541 goes to sleep mode? PCIe controller will not go to D3 hot state automatically. Software has to write Powerstate field of PMCSR register. If the downstream component is in D3 hot state, then permissible states for Upstream component are D0-D3hot. Refer Section 5.3.2 of Base specification 1.0a The Bus states are L1 or L2/L3 Ready if the power is going to be removed. The procedure for entry into these states is described in Section 5.3.2.1 and 5.3.2.3 What internal interrupt numbers are assigned to PCIe1 through PCIe3 in MPC8541? All PCIe interrupts in MPC8541 are error interrupts and are ORed with other error interrupts to result in "Error" which is mapped to #0 of the OPIC.

Can you please confirm that the MPC8541 ethernet input clock is actually 2 clocks: one for each eTSEC, with name TSECn_GTX_CLK125/GPIOm? The MPC8541 ballmap spreadsheet only shows one gtx_clk125 pin (like the 8536), but the current data sheet (Revision E) indicates there are two. The ball map shows only primary functions of a pin. By default both the eTSECs would share the same clock i.e TSEC1_GTX_CLK125 @Y29. If required, user can opt to use separate clock for eTSEC2. The separate clock for eTSEC2 is multiplexed with TSEC_1588_TRIG_IN1@AH27 and can be configured using PMUXCR[6:7].

The SD card spec requires SD clock to supply for at least 74 clock cycles. On the other hand, the eSDHC controller in MPC8541 supplies about 13 SD clock cycles (with 180 degrees phase shift) at power up. Will SD card have any reliability issue by this fewer clock cycles than what is required by spec? No, SD card should not have the reliability issue. 74 clocks can be supplied by setting SYSCTL [INITA]. The 180 degree phase shift will not affect card or eSDHC IP block's operation. The phase shift is due to the synchronizer.

For MPC8541, when I am using a DDR controller with a 64-bit interface with a 32-bit memory sub system, which lanes should I use? When a 64-bit DDR interface is configured in a 32-bit data bus width, lanes [0:3] (MDQ [0:31]) will be used.

For MPC8541, what is the maximum bit rate clock for SSI? Is it really 12.285MHz or can it be run up to platform clock / 8? Maximum bit rate clock for SSI is as per hardware spec i.e. 12.285MHz. This is the maximum speed at which the SSI IP is guaranteed to work. From a system perspective it is possible to clock it at a higher speed, but for MPC8541 that is not supported. If platform clock is 400MHz, please use appropriate values of DIV2, PSR and PM to ensure that the bit rate clock for SSI does not exceed 12.285MHz.

Can MPC8541 GPIO signals drive LEDs directly? What is the output current requirement (Iol / Ioh) for GPIO signals? Yes, MPC8541 GPIO signals can drive LEDs directly. When GPIO is driven HIGH, to maintain a voltage of 2.4V, no more than 2mA should be drawn from the IO and conversely to maintain a 0.4V when GPIO is driven LOW no more than 2mA should be sunk into the IO. Current limiting would have to be done through external resistors. Below are the current and voltage requirements: @3.3V Input high voltage VIH 2V Input low voltage VIL 0.8V Input current (OVIN = 0 V or OVIN = OVDD) IIN — ±40 μA2 Output high voltage (OVDD = min, IOH = –2 mA) VOH 2.4V Output low voltage (OVDD = min, IOL = 2 mA) VOL 0.4V @2.5V Input high voltage VIH 1.7V Input low voltage VIL 0.7V Input current (OVIN = 0 V or OVIN = OVDD) IIN — ±40 μA2 Output high voltage (OVDD = min, IOH = –2 mA) VOH 1.7V Output low voltage (OVDD = min, IOL = 2 mA) VOL 0.7V @1.8V Input high voltage VIH 1.2V Input low voltage VIL 0.6V Input current (OVIN = 0 V or OVIN = OVDD) IIN — ±40 μA2 Output high voltage (OVDD = min, IOH = –0.5 mA) VOH 1.35V Output low voltage (OVDD = min, IOL = 0.5 mA) VOL 0.4V MPC8541EC revision F defines output delay time for eSDHC interface in table 52. Is there any specification regarding "output hold" time? If not, how should I consider about it? The min value of Output delay time becomes the output hold. ( Half clock period - |min khov| ) becomes the input hold for the receiver chip. How is the selection between eLBC and DIU signals done in MPC8541? Is it done through SPI signals? Why are SPI signals "-" in data phase of 16-bit GPCM? Selection between eLBC and DIU signals is done via PMUXCR [eLBC_DIU], and INDEPENDENTLY selection between eSPI, eLBC or eSDHC signals is done via PMUXCR[SPI_eLBC]. Thus for SPI signals user only needs to use PMUXCR[SPI_eLBC]. And for 32-bit GPCM user has to set BOTH PMUXCR[eLBC_DIU] and PMUXCR[SPI_eLBC]. Using the TDM interface in shared mode (Tx clk and sync are used for Tx and Rx), are pullups / pulldowns required for TDM_RCK and TDM_RFS in MPC8541? Actually the multiplexing happens at the SoC level and the selection of shared mode happens at the IP level, hence pins would not automatically revert to GPIO. It is recommended to be pulled to OVdd by 2k-10k. Can you please describe the procedure for timer soft reset and reconfiguration for MPC8541? Software must do the following before asserting TMR_CTRL[TMSR]: 1) Place the controller in graceful transmit stop (DMACTL[GTS]=1, wait for IEVENTGn[GTSC]=1) 2) Disable receive (MACCFG1[RX_EN]=0) Note: After setting timer soft reset (TMR_CTRL[TMSR]), software must leave the bit high for at least three 1588 reference clocks or tx_clk cycles, whichever is slower, before clearing the bit. How should I handle 2 CKSTP_OUT signals for MPC8541? Note 11 on Table 1 in the MPC8541EC states that these need a weak pullup resistor. However, Table 4-13 in the MPC8541RM shows that these 2 signal default to 1 (as part of cfg_rom_loc). Do these pins need pullups? The internal pull up for por_cfg pins is only for the duration when HRESET is asserted. So after POR pull up will be required. For handling this kind of a situation a tri state buffer with Enable tied to HRESET can be used. Add pull down at buffer input and pull up at buffer output. While HRESET is asserted, the pull down is visible on the buffer output. After HRESET deassertion, buffer output is tri stated and pull up on the output of buffer pulls up the CKSTP_OUT signal. What is the default value of POWER_EN pin in EXTEST and on BYPASS/IDCODE mode in MPC8541? Default values in modes for EXTEST and BYPASS/IDCODE: 1) EXTEST Normally SAMPLE-PRELOAD is run prior to the EXTEST instruction whose purpose is to configure BIDI PADS either as input or output. In this state we shift the value in BSR chain so depending upon value shifted in BSR this pin would have that value. 2) IDCODE and BYPASS Pin is at the functional value. These instructions don’t have any effect on the pin value.

Note 2 of table 13 in MPC6536 hardware spec mentions: "Peak-to-peak noise on MVREFn may not exceed +/- 1% of the DC value." What is "the DC value"? The DC value is the GVdd value. Do you have any typical estimated numbers for running at 3.0Gsb vs running at 1.5Gbs for MPC8536? Would there be any significant power savings? The 8536 SATA I/O power consumptions for 1.5Gb is 240 mW and for 3.0Gb is 270 mW.

MPC8536 Hardware spec states that either SDHC_CD, or SDHC_DAT3 can be used for card detection. Do you have to set the bit PROCTL[D3CD] specifically, if you want to use the DAT[3] method? This, plus adding the pull-down? PROCTL[D3CD] has to be set to 1 if DAT3 is used as card detection. A pull down is needed as well per spec. It should be an external pull down. MPC8536 HW spec mentions that if SDHC_DAT[3] is not used, SDHC_CD must be used, but it can be implemented by GPIO. What does that mean? Does it mean external (non CPU) GPIO could trigger the SDHC_CD transition? If DAT3 is not used as card detection pin, a separate pin has to be used. For 8536, SDHC_CD_B/GPIO[4] pin is used. PMUXCR[SDHC_CD] pin should set to 1. If PROCTL[D3CD] =0 & PMUXCR[SDHC_CD]=0, the PRSSTAT[CDPL] field is unaffected by the external card detect pin, and will permanently indicate that a card is present.

Is it correct that TIMING_CFG_5[RODT_ON] and TIMING_CFG_5[RODT_OFF] do not affect internal ODT circuit for MPC8536? These values are always set in u-boot for our DDR3 based boards (e.g. P2020DS, MPC8569MDS). However external ODT is never enabled for SDRAM reads, this could lead to a conclusion that internal ODT is also affected by the TIMING_CFG_5 setting. Can you comment? TIMING_CFG_5 register is only for DRAM ODT (external ODT), this is verified and confirmed. As for your suggestion that because in most cases the read ODT on DRAM is off and hence it has something to do with internal ODT is not a valid assumption. The Read ODT for DRAM is an option available if required. In most cases it will not apply, but there may be a configuration that may require it and then the option is available for such users. Please clarify the meaning of TIMING_CFG_5 register for DDR3 controller of the MPC8536. The sentence ".. relevant ODT signal(s)" is common to all fields. What is this referring to? Is that both a) an internal signal controlling internal IOs (enabled by CFG_2[ODT_CFG]) and b) the external MODT[] signals going to the SDRAM? If yes, what is the delay between the assertion of the internal ODT signal (e.g. set by TIMING_CFG_5[RODT_ON])and actual switching of the internal RTT? These are related to the ODT timings to the DRAM. If ODT during reads is not used, then the RODT_ON and RODT_OFF values can be cleared. These are the ODT signal turn ON/OFF latency. For DDR3 it is defined as WL-2=CWL+AL-2. If one DIMM slot is used then there is no need for dynamic ODT setting.

MPC8536 PCI controller can get clock from SYSCLK (synchronous) or from PCICLK (PCI asynchronous mode). If PCI is configured as PCI asynchronous mode, a valid clock must be provided on pin PCICLK, otherwise the processor will not boot up. Is this limit just due to PCI bus specs and if PCI is not used then MPC8536 PCI block can withstand 125MHz in synchronous mode? The PCI input clock frequency spec range is between 33 - 66MHz. IF the PCI interface is enabled, then this spec here will matter regardless whether you are running in synchronous or asynchronous mode. IF the PCI is disabled / un-used, it will not matter what input clock is being fed into this interface. Also, please refer to section 15.2 of the 8536 bring-up guide for termination details of the PCI pins including the PCI1_CLK pin when the interface is not being used. I am starting 8536 design making use of both SerDes serial interfaces: 1) SerDes1: PCI Express 1 (x4) (2.5 Gbps) → SerDes1 Lanes A-D; PCI Express 2 (x1) (2.5 Gbps) → SerDes1 Lanes E-F 2) SerDes2: SATA1 → SerDes2 Lane A. Each SerDes has its own reference clock. They will both run at 100MHz. Are there any phase requirements between these 2 clocks? There is no requirement on 8536 for any particular phase relationship between reference clock for Serdes 1 vs Serdes 2 because each serdes is completely independent.

Note 2 of table 13 in MPC8535 hardware spec mentions: "Peak-to-peak noise on MVREFn may not exceed +/- 1% of the DC value." What is "the DC value"? The DC value is the GVdd value. Do you have any typical estimated numbers for running at 3.0Gsb vs running at 1.5Gbs for MPC8535? Would there be any significant power savings? The 8535 SATA I/O power consumptions for 1.5Gb is 240 mW and for 3.0Gb is 270 mW.

MPC8535 Hardware spec states that either SDHC_CD, or SDHC_DAT3 can be used for card detection. Do you have to set the bit PROCTL[D3CD] specifically, if you want to use the DAT[3] method? This, plus adding the pull-down? PROCTL[D3CD] has to be set to 1 if DAT3 is used as card detection. A pull down is needed as well per spec. It should be an external pull down. MPC8535 HW spec mentions that if SDHC_DAT[3] is not used, SDHC_CD must be used, but it can be implemented by GPIO. What does that mean? Does it mean external (non CPU) GPIO could trigger the SDHC_CD transition? If DAT3 is not used as card detection pin, a separate pin has to be used. For 8535, SDHC_CD_B/GPIO[4] pin is used. PMUXCR[SDHC_CD] pin should set to 1. If PROCTL[D3CD] =0 & PMUXCR[SDHC_CD]=0, the PRSSTAT[CDPL] field is unaffected by the external card detect pin, and will permanently indicate that a card is present.

Is it correct that TIMING_CFG_5[RODT_ON] and TIMING_CFG_5[RODT_OFF] do not affect internal ODT circuit for MPC8535? These values are always set in u-boot for our DDR3 based boards (e.g. P2020DS, MPC8569MDS). However external ODT is never enabled for SDRAM reads, this could lead to a conclusion that internal ODT is also affected by the TIMING_CFG_5 setting. Can you comment? TIMING_CFG_5 register is only for DRAM ODT (external ODT), this is verified and confirmed. As for your suggestion that because in most cases the read ODT on DRAM is off and hence it has something to do with internal ODT is not a valid assumption. The Read ODT for DRAM is an option available if required. In most cases it will not apply, but there may be a configuration that may require it and then the option is available for such users. Please clarify the meaning of TIMING_CFG_5 register for DDR3 controller of the MPC8535. The sentence ".. relevant ODT signal(s)" is common to all fields. What is this referring to? Is that both a) an internal signal controlling internal IOs (enabled by CFG_2[ODT_CFG]) and b) the external MODT[] signals going to the SDRAM? If yes, what is the delay between the assertion of the internal ODT signal (e.g. set by TIMING_CFG_5[RODT_ON])and actual switching of the internal RTT? These are related to the ODT timings to the DRAM. If ODT during reads is not used, then the RODT_ON and RODT_OFF values can be cleared. These are the ODT signal turn ON/OFF latency. For DDR3 it is defined as WL-2=CWL+AL-2. If one DIMM slot is used then there is no need for dynamic ODT setting.