Please confirm that a PCIe lane on the P1023 can be enabled after POR (configured off in h/w but turned on in s/w). If so how this would be implemented? It is possible to control PCIe Lane turned on through s/w. You can control this through SRDSCR2 [0:7]. Through this control you can power -up or power- down individual lanes separately What is the difference between two strap options for PCIe ports - 0b00 or 0b11? In terms of PCIe, options 0b00 and 0b11 are redundant, but in terms of SGMII, they are different 0b00 - 2 lanes are for PCIe; the remaining 2 lanes are powered down 0b11 - 2 lanes are for PCIe; the remaining 2 lanes are for SGMII 0b01 - 3 lanes are for PCIe; the remaining 1 lane is powered down 0b10 - 3 lanes are for PCIe; the remaining 1 lane is for SGMII When SGMII is not used, the corresponding lane(s) should be powered down to save power.

How can I ensure that Ethernet flow control is turned on through the register setting in P1015? Please try the below steps to enable Ethernet flow control: 1) Set MACCFG1[Rx_Flow] && MACCFG1[Tx_Flow] to 1 2) Set RCTRL[LFC] to 1. Setting the flow control bits Rx_Flow and Tx_Flow means that the MAC can detect and act on PAUSE flow control frames, receive and transmit respectively. There are two ways you can confirm or see them in action: 1) Software sending a PAUSE frame through TCTRL[TFC_PAUSE] 2) Changing some hidden FIFO threshold registers, such that the FIFO is about to overflow and that triggers eTSEC logic to send a PAUSE.

Can the P1015 eSPI controller address 4-byte (32-bit) addressable EEPROMs in any situation? Yes, eSPI controller addresses 4-byte addressable EEPROMs in any situation. For P1015, is it possible to boot from a 4-byte EEPROM using the on-chip ROM? No. The software in the on-chip ROM only supports 16-bit addressable or 24-bit addressable EEPROMs.

Does P1025 support 16 bits DDR3? I found DDR_SDRAM_CFG{DBW] can be set to 16bits. But no 16bits DDR3 feature is claimed? Theoretically the DDR controller supports 16 bit mode. But the mode has not been tested/verified/validated in P1025. We recommend you to not use 16 mode of P1025. “In asynchronous mode, the memory bus clock speed must be less than or equal to the CCB clock rate which in turn must be less than the DDR PLL rate." Is this statement correct for P1025? No it is not correct. The correct statement is " In asynchronous mode, if the ratio of the DDR data rate to the CCB clock rate is greater than 3 :1 ( i.e. DDR=3:CCB=1 ), than the DDR performance monitor statistic accuracy cannot be guaranteed."

P1016 spec says that the QUICC engine periodically polls its Rx/Tx rings and if a BD is not empty, checks the ownership flag and moves to the next step. How does the user application trigger/control the QE to start polling? For TX BD ring, (after configured) QE will periodically poll the ring and process the BD that is not empty and then move to next BD. When a BD is actually transmitted, a "transmission complete" event (and interrupt if enabled) will be generated, so the BD/Buffer can be released. For RX BD ring, (after configured) QE will pre-fetch a BD and then process the BD when data is received. When a packet (frame) is received, a "received" event (and interrupt if enabled) will be generated, so the BD/Buffer can be released/processed. If no empty BD is available during the pre-fetch, an "out-of-BD" error will be reported. Is there any suggested approach to determining the tx/rx ring buffer sizes on the peripherals that interface to the UCC? How can I decide on the ring size? The bandwidth would be 45 Mbps. The MTU on the serial interface can range up to 16k Bytes. Even if MTU could be 16K bytes, the average frame could be much smaller. Find out the average frame size and pick up a buffer size that is bit larger than the average frame size. This usually creates a good balance of efficiency between processing time and memory usage. It is much more efficient in terms of processing time to process a frame of 16K in one BD/Buffer of 16K size than in 16 BDs/Buffers of 1K size. However, if all buffers are 16K size while 90% of the frames are 1K, most memory is wasted. Generally, the ring size should be equal to the number of BD’s required to accommodate the largest possible frame size + 4 extra BDs. However, over here the bandwidth is relatively high (45M) and could be quite bursty. Hence we would suggest starting with "TWO largest possible frame size + 4 extra BDs"

Do we have an internal pull up on LA20 pin in P1015E? According to hardware spec for P1015/P1024, LA20 pin is a reset configuration pin. It has a weak internal pull-up P-FET which is enabled only when the processor is in the reset state. This pull-up is designed such that it can be overpowered by an external 4.7-kΩ pull-down resistor. Assuming that I did not include a pull up or pull down and assuming no device was asserting LA20--what state do we sample at POR? If LA20 is left floating at POR, would one read the SVR for P1015E (80ED0211) OR P1011E (80ED0011)? According to hardware spec for P1015/P1024, LA20 pin "must be pulled down with a 4.7K resistor". So the default in case that a design doesn't include an external pull (as required by the spec) is for it to sample as a '1'. Leaving the pin NC (floating) at POR is effectively an out of spec configuration.

Can a spread spectrum clock be used for the 66.66 Mhz DDR clock of the P1023? If so what percentage spread is allowed and what modulation frequency? Yes, a spread spectrum clock can be used for 66.66 Mhz DDR clock. Please refer to below table for details: Spread Spectrum Clock Source Recommendations Parameter Min Max Unit Frequency modulation — 60 kHz Frequency spread — 1.0  % For P1023 package, which is the GTX clock pin for TSEC1 and TSEC2? According to the P1023 ballmap, V21 is the GTX clock pin of TSEC1 and T19 is the GTX clock pin of TSEC2.

Please specify the DDR read only and write only counters for P1023. Event 19 counts DDR reads only while event 27 counts DDR writes only in P1023. How are DDR errors cleared in the ESUMR reg (bit 8)? Do they need to re-init the DDR? You need to clear the ERR_DEFECT [MBE] bit (write 1 to clear). After that the ESUMR bit 8 will be cleared.