P-Series Knowledge Base

cancel
Showing results for 
Search instead for 
Did you mean: 

P-Series Knowledge Base

Discussions

Sort by:
P1010 has only a single pair of MCK signal, while my device has four Chip Select signals. In a scenario connecting a lot of memory devices under four CS, can the single pair of MCK really drive all of memory devices which are connected by fly-by topology on each CS? In case of P1010 (which has only one MCK), is it really practical to connect DDR3 memory devices under all of four CS? Would it be necessary to use "external CLK buffer" in such a case using four CS? P1010 was designed for low-cost systems, and as such some of the pins seen on other QorIQ devices (CKE2/3, ODT2/3) were removed to save on cost. For a single-rank, fly-by topology, only one CS would be used. If more ranks were needed, this would be addressed with stacked memories (DDR3 devices that take up to four CS signals). How does one set up the P1010 or P1014 for a 16 bit data bus size? To set the data bus width, you need to set DDR_SDRAM_CFG[DBW] bits of the register given in section 9.4.1.7, Page-9-20 of P1010RM Rev-B. Is it allowed to use four chip-selects with P1010? In my understanding, one ODT signal should be used and be controlled per chip-select? However P1010 has two MODT. P1010 is designed to use only one chip select with discrete DDR3 DRAM. This requires one CS, one ODT, and one CKE with one clock pair. Additional CS/ODT/CKE are designed for using stacked die DDR3 DRAMs. The four CS, two ODT & CKE, are useful if dual or quad stacked die discrete DDR3 DRAM were used. For the write leveling, does the P1010 use DQ[0,8,16,24] or use all DQ bit to drive status back to the DDR controller? P1010 DDR controller can support the write leveling status on any of the data bits within the data byte from a JEDEC standard DDR3 SDRAM.
View full article
Routing the DDR Memory Channel To help ensure the DDR interface is properly optimized, Freescale recommends routing the DDR memory channel in this specific order: 1. Data 2. Address/command/control 3. Clocks Note: The address/command, control, and data groups all have a relationship to the routed clock. Therefore, the effective clock lengths used in the system must satisfy multiple relationships. It is recommended that the designer perform simulation and construct system timing budgets to ensure that these relationships are properly satisfied. Routing DDR3 Data Signals The DDR interface data signals (MDQ[0:63], MDQS[0:8], MDM[0:8], and MECC[0:7]) are source-synchronous signals by which memory and the controller capture the data using the data strobe rather than the clock itself. When transferring data, both edges of the strobe are used to achieve the 2x data rate. An associated data strobe (DQS and DQS) and data mask (DM) comprise each data byte lane. This 11-bit signal lane relationship is crucial for routing (see Table 1). When length-matching, the critical item is the variance of the signal lengths within a given byte lane to its strobe. Length matching across all bytes lanes is also important and must meet the t DQSS parameter as specified by JEDEC. This is also commonly referred to as the write data delay window. Typically, this timing is considerably more relaxed than the timing of the individual byte lanes themselves: Table 1: Byte Lane to Data Strobe and Data Mask Mapping Data Data Strobe Data Mask Lane Number MDQ[0:7] MDQS0, MDQS0 MDM0 Lane 0 MDQ[8:15] MDQS1, !MDQS1 MDM1 Lane 1 MDQ[16:23] MDQS2, !MDQS2 MDM2 Lane 2 MDQ[24:31] MDQS3, !MDQS3 MDM3 Lane 3 MDQ[32:39] MDQS4, !MDQS4 MDM4 Lane 4 MDQ[40:47] MDQS5, !MDQS5 MDM5 Lane 5 MDQ[48:55] MDQS6, !MDQS6 MDM6 Lane 6 MDQ[56:63] MDQS7, !MDQS7 MDM7 Lane 7 MECC[0:7] MDQS8, !MDQS8 MDM8 Lane 8 DDR Signal Group Layout Recommendations Table 2 lists the layout recommendations for DDR signal groups and the benefit of following each recommendation: Table 2: DDR Signal Groups Layout Recommendations Recommendation Benefit Route each data lane adjacent to a solid ground reference for the entire route to provide the lowest inductance for the return currents Provides the optimal signal integrity of the data interface Note: This concern is especially critical in designs that target the top-end interface speed, because the data switches at 2x the applied clock When the byte lanes are routed, route signals within a byte lane on the same critical layer as they traverse the PCB motherboard to the memories Helps minimize the number of vias per trace and provides uniform signal characteristics for each signal within the data group Alternate the byte lanes on different critical layers Facilitates ease of break-out from the controller perspective, and keeps the signals within the byte group together
View full article
Routing the DDR Memory Channel To help ensure the DDR interface is properly optimized, Freescale recommends routing the DDR memory channel in this specific order: 1. Data 2. Address/command/control 3. Clocks Note: The address/command, control, and data groups all have a relationship to the routed clock. Therefore, the effective clock lengths used in the system must satisfy multiple relationships. It is recommended that the designer perform simulation and construct system timing budgets to ensure that these relationships are properly satisfied. Routing DDR3 Data Signals The DDR interface data signals (MDQ[0:63], MDQS[0:8], MDM[0:8], and MECC[0:7]) are source-synchronous signals by which memory and the controller capture the data using the data strobe rather than the clock itself. When transferring data, both edges of the strobe are used to achieve the 2x data rate. An associated data strobe (DQS and DQS) and data mask (DM) comprise each data byte lane. This 11-bit signal lane relationship is crucial for routing (see Table 1). When length-matching, the critical item is the variance of the signal lengths within a given byte lane to its strobe. Length matching across all bytes lanes is also important and must meet the t DQSS parameter as specified by JEDEC. This is also commonly referred to as the write data delay window. Typically, this timing is considerably more relaxed than the timing of the individual byte lanes themselves: Table 1: Byte Lane to Data Strobe and Data Mask Mapping Data Data Strobe Data Mask Lane Number MDQ[0:7] MDQS0, MDQS0 MDM0 Lane 0 MDQ[8:15] MDQS1, !MDQS1 MDM1 Lane 1 MDQ[16:23] MDQS2, !MDQS2 MDM2 Lane 2 MDQ[24:31] MDQS3, !MDQS3 MDM3 Lane 3 MDQ[32:39] MDQS4, !MDQS4 MDM4 Lane 4 MDQ[40:47] MDQS5, !MDQS5 MDM5 Lane 5 MDQ[48:55] MDQS6, !MDQS6 MDM6 Lane 6 MDQ[56:63] MDQS7, !MDQS7 MDM7 Lane 7 MECC[0:7] MDQS8, !MDQS8 MDM8 Lane 8 DDR Signal Group Layout Recommendations Table 2 lists the layout recommendations for DDR signal groups and the benefit of following each recommendation: Table 2: DDR Signal Groups Layout Recommendations Recommendation Benefit Route each data lane adjacent to a solid ground reference for the entire route to provide the lowest inductance for the return currents Provides the optimal signal integrity of the data interface Note: This concern is especially critical in designs that target the top-end interface speed, because the data switches at 2x the applied clock When the byte lanes are routed, route signals within a byte lane on the same critical layer as they traverse the PCB motherboard to the memories Helps minimize the number of vias per trace and provides uniform signal characteristics for each signal within the data group Alternate the byte lanes on different critical layers Facilitates ease of break-out from the controller perspective, and keeps the signals within the byte group together
View full article
Routing the DDR Memory Channel To help ensure the DDR interface is properly optimized, Freescale recommends routing the DDR memory channel in this specific order: 1. Data 2. Address/command/control 3. Clocks Note: The address/command, control, and data groups all have a relationship to the routed clock. Therefore, the effective clock lengths used in the system must satisfy multiple relationships. It is recommended that the designer perform simulation and construct system timing budgets to ensure that these relationships are properly satisfied. Routing DDR3 Data Signals The DDR interface data signals (MDQ[0:63], MDQS[0:8], MDM[0:8], and MECC[0:7]) are source-synchronous signals by which memory and the controller capture the data using the data strobe rather than the clock itself. When transferring data, both edges of the strobe are used to achieve the 2x data rate. An associated data strobe (DQS and DQS) and data mask (DM) comprise each data byte lane. This 11-bit signal lane relationship is crucial for routing (see Table 1). When length-matching, the critical item is the variance of the signal lengths within a given byte lane to its strobe. Length matching across all bytes lanes is also important and must meet the t DQSS parameter as specified by JEDEC. This is also commonly referred to as the write data delay window. Typically, this timing is considerably more relaxed than the timing of the individual byte lanes themselves: Table 1: Byte Lane to Data Strobe and Data Mask Mapping Data Data Strobe Data Mask Lane Number MDQ[0:7] MDQS0, MDQS0 MDM0 Lane 0 MDQ[8:15] MDQS1, !MDQS1 MDM1 Lane 1 MDQ[16:23] MDQS2, !MDQS2 MDM2 Lane 2 MDQ[24:31] MDQS3, !MDQS3 MDM3 Lane 3 MDQ[32:39] MDQS4, !MDQS4 MDM4 Lane 4 MDQ[40:47] MDQS5, !MDQS5 MDM5 Lane 5 MDQ[48:55] MDQS6, !MDQS6 MDM6 Lane 6 MDQ[56:63] MDQS7, !MDQS7 MDM7 Lane 7 MECC[0:7] MDQS8, !MDQS8 MDM8 Lane 8 DDR Signal Group Layout Recommendations Table 2 lists the layout recommendations for DDR signal groups and the benefit of following each recommendation: Table 2: DDR Signal Groups Layout Recommendations Recommendation Benefit Route each data lane adjacent to a solid ground reference for the entire route to provide the lowest inductance for the return currents Provides the optimal signal integrity of the data interface Note: This concern is especially critical in designs that target the top-end interface speed, because the data switches at 2x the applied clock When the byte lanes are routed, route signals within a byte lane on the same critical layer as they traverse the PCB motherboard to the memories Helps minimize the number of vias per trace and provides uniform signal characteristics for each signal within the data group Alternate the byte lanes on different critical layers Facilitates ease of break-out from the controller perspective, and keeps the signals within the byte group together
View full article
The on-chip ROM code does not set up any local access windows (LAWs). Access to the CCSR address space or the L2 cache does not require a LAW. It is the user’s responsibility to set up a LAW through a control word address/data pair for the desired target address and execution starting address (which is typically in either DDR or local bus memory space).   Required Configurations for SD Card/MMC Booting The configuration settings required to boot from an SD card/MMC are as follows: Ensure that cfg_rom_loc[0:3] (Boot_Rom_Loc) are driven with a value of 0b0111. Only one core can be in booting mode. If your device has multiple cores, all other cores must be in a boot hold-off mode. The CPU boot configuration input, cfg_cpux_boot, should be 0, where x is from 1 to n (n = the number of cores). Booting from the eSDHC interface can occur from different SD card slots if multiple SD card slots are designed on the board. In this case, ensure the appropriate SD card/MMC is selected For example, on the P1022 board, bit 7 of the SW8 is used to select which SD/MMC slot is used. If SW8[7] = 1, an SD card/MMC must be put to the external SD card/MMC slot (J1). TIP The polarity of the SDHC_CD signal should be active-low.   Required Configurations for EEPROM Booting The configuration settings required to boot from an EEPROM are as follows: Ensure that cfg_rom_loc[0:3] (Boot_Rom_Loc) are driven with a value of 0b0110. Only one core can be in booting mode. If your device has multiple cores, all other cores must be in a boot hold-off mode. The CPU boot configuration input, cfg_cpux_boot, should be 0, where x is from 1 to n (n = the number of cores). The eSPI chip select 0 (SPI_CS[0]) must be connected to the EEPROM that is used for booting. No other chip select can be used for booting. This is because during booting, the eSPI controller is configured to operate in master mode. Booting from the eSPI interface only works with SPI_CS[0].  
View full article
The on-chip ROM code does not set up any local access windows (LAWs). Access to the CCSR address space or the L2 cache does not require a LAW. It is the user’s responsibility to set up a LAW through a control word address/data pair for the desired target address and execution starting address (which is typically in either DDR or local bus memory space). Required Configurations for SD Card/MMC Booting The configuration settings required to boot from an SD card/MMC are as follows: Ensure that cfg_rom_loc[0:3] (Boot_Rom_Loc) are driven with a value of 0b0111. Only one core can be in booting mode. If your device has multiple cores, all other cores must be in a boot hold-off mode. The CPU boot configuration input, cfg_cpux_boot, should be 0, where x is from 1 to n (n = the number of cores). Booting from the eSDHC interface can occur from different SD card slots if multiple SD card slots are designed on the board. In this case, ensure the appropriate SD card/MMC is selected For example, on the P1021 board, bit 7 of the SW8 is used to select which SD/MMC slot is used. If SW8[7] = 1, an SD card/MMC must be put to the external SD card/MMC slot (J1). TIP The polarity of the SDHC_CD signal should be active-low.  Required Configurations for EEPROM Booting The configuration settings required to boot from an EEPROM are as follows: Ensure that cfg_rom_loc[0:3] (Boot_Rom_Loc) are driven with a value of 0b0110. Only one core can be in booting mode. If your device has multiple cores, all other cores must be in a boot hold-off mode. The CPU boot configuration input, cfg_cpux_boot, should be 0, where x is from 1 to n (n = the number of cores). The eSPI chip select 0 (SPI_CS[0]) must be connected to the EEPROM that is used for booting. No other chip select can be used for booting. This is because during booting, the eSPI controller is configured to operate in master mode. Booting from the eSPI interface only works with SPI_CS[0].
View full article
The on-chip ROM code does not set up any local access windows (LAWs). Access to the CCSR address space or the L2 cache does not require a LAW. It is the user’s responsibility to set up a LAW through a control word address/data pair for the desired target address and execution starting address (which is typically in either DDR or local bus memory space). Required Configurations for SD Card/MMC Booting The configuration settings required to boot from an SD card/MMC are as follows: Ensure that cfg_rom_loc[0:3] (Boot_Rom_Loc) are driven with a value of 0b0111. Only one core can be in booting mode. If your device has multiple cores, all other cores must be in a boot hold-off mode. The CPU boot configuration input, cfg_cpux_boot, should be 0, where x is from 1 to n (n = the number of cores). Booting from the eSDHC interface can occur from different SD card slots if multiple SD card slots are designed on the board. In this case, ensure the appropriate SD card/MMC is selected For example, on the P1020 board, bit 7 of the SW8 is used to select which SD/MMC slot is used. If SW8[7] = 1, an SD card/MMC must be put to the external SD card/MMC slot (J1). TIP The polarity of the SDHC_CD signal should be active-low. Required Configurations for EEPROM Booting The configuration settings required to boot from an EEPROM are as follows: Ensure that cfg_rom_loc[0:3] (Boot_Rom_Loc) are driven with a value of 0b0110. Only one core can be in booting mode. If your device has multiple cores, all other cores must be in a boot hold-off mode. The CPU boot configuration input, cfg_cpux_boot, should be 0, where x is from 1 to n (n = the number of cores). The eSPI chip select 0 (SPI_CS[0]) must be connected to the EEPROM that is used for booting. No other chip select can be used for booting. This is because during booting, the eSPI controller is configured to operate in master mode. Booting from the eSPI interface only works with SPI_CS[0].
View full article
Routing the DDR Memory Channel To help ensure the DDR interface is properly optimized, Freescale recommends routing the DDR memory channel in this specific order: 1. Data 2. Address/command/control 3. Clocks Note: The address/command, control, and data groups all have a relationship to the routed clock. Therefore, the effective clock lengths used in the system must satisfy multiple relationships. It is recommended that the designer perform simulation and construct system timing budgets to ensure that these relationships are properly satisfied. Routing DDR3 Data Signals The DDR interface data signals (MDQ[0:63], MDQS[0:8], MDM[0:8], and MECC[0:7]) are source-synchronous signals by which memory and the controller capture the data using the data strobe rather than the clock itself. When transferring data, both edges of the strobe are used to achieve the 2x data rate. An associated data strobe (DQS and DQS) and data mask (DM) comprise each data byte lane. This 11-bit signal lane relationship is crucial for routing (see Table 1). When length-matching, the critical item is the variance of the signal lengths within a given byte lane to its strobe. Length matching across all bytes lanes is also important and must meet the t DQSS parameter as specified by JEDEC. This is also commonly referred to as the write data delay window. Typically, this timing is considerably more relaxed than the timing of the individual byte lanes themselves: Table 1: Byte Lane to Data Strobe and Data Mask Mapping MDQ[0:7] MDQS0, MDQS0 MDM0 Lane 0 MDQ[8:15] MDQS1, !MDQS1 MDM1 Lane 1 MDQ[16:23] MDQS2, !MDQS2 MDM2 Lane 2 MDQ[24:31] MDQS3, !MDQS3 MDM3 Lane 3 MDQ[32:39] MDQS4, !MDQS4 MDM4 Lane 4 MDQ[40:47] MDQS5, !MDQS5 MDM5 Lane 5 MDQ[48:55] MDQS6, !MDQS6 MDM6 Lane 6 MDQ[56:63] MDQS7, !MDQS7 MDM7 Lane 7 MECC[0:7] MDQS8, !MDQS8 MDM8 Lane 8 DDR Signal Group Layout Recommendations Table 2 lists the layout recommendations for DDR signal groups and the benefit of following each recommendation: Table 2: DDR Signal Groups Layout Recommendations Route each data lane adjacent to a solid ground reference for the entire route to provide the lowest inductance for the return currents Provides the optimal signal integrity of the data interface Note: This concern is especially critical in designs that target the top-end interface speed, because the data switches at 2x the applied clock When the byte lanes are routed, route signals within a byte lane on the same critical layer as they traverse the PCB motherboard to the memories Helps minimize the number of vias per trace and provides uniform signal characteristics for each signal within the data group Alternate the byte lanes on different critical layers Facilitates ease of break-out from the controller perspective, and keeps the signals within the byte group together
View full article