GPMC
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• Write enable signal WEn
– WEn assertion indicates a read cycle.
– WEn assertion time is controlled by the GPMC_CONFIG4_i[19-16] WEONTIME field.
– WEn deassertion time is controlled by the GPMC_CONFIG4_i[28-24] WEOFFTIME field.
The WEn falling edge must not be used to control the time when the burst first data is driven in the
address/data bus because some new devices require the WEn signal at low during the address phase.
• Direction signal DIR is OUT during the entire access.
When the GPMC generates a write access to an AAD-multiplexed device, all address bits are driven onto
the address/data bus in two separate phases. The first phase is used for the MSB address and is qualified
with OEn driven low. The second phase for LSB address is qualified with OEn driven high. The address
phase ends at WEn assertion time.
The CSn and DIR signals are controlled as detailled above.
• Address valid signal ADVn is asserted and deasserted twice during a read transaction
– ADVn first assertion time is controlled by the GPMC_CONFIG3_i[[6-4] ADVAADMUXONTIME field.
– ADVn first deassertion time is controlled by the GPMC_CONFIG3_i[[26-24]
ADVAADMUXRDOFFTIME field.
– ADVn second assertion time is controlled by the GPMC_CONFIG3_i[[3-0] ADVONTIME field.
– ADVn second deassertion time is controlled by the GPMC_CONFIG3_i[[12-8] ADVRDOFFTIME
field.
• Output Enable signal OEn is asserted and deasserted twice during a read transaction (OEn second
assertion indicates a read cycle)
– OEn first assertion time is controlled by the GPMC_CONFIG4_i[[6-4] OEAADMUXONTIME field.
– OEn first deassertion time is controlled by the GPMC_CONFIG4_i[15-13] OEAADMUXOFFTIME
field.
– OEn second assertion time is controlled by the GPMC_CONFIG4_i[3-0] OEONTIME field.
– OEn second deassertion time is controlled by the GPMC_CONFIG4_i[12-8] OEOFFTIME field.
First write data is driven by the GPMC at GPMC_CONFIG6_i[19-16] WRDATAONADMUXBUS, when in
address/data mux configuration. The next write data of the burst is driven on the bus at WRACCESSTIME
+ 1 during GPMC_CONFIG5_i[27-24] PAGEBURSTACCESSTIME GPMC_FCLK cycles. The last data of
the synchronous burst write is driven until GPMC_CONFIG5_i[12-8] WRCYCLETIME completes.
• WRACCESSTIME is defined in the GPMC_CONFIG6_i[28-24] register.
• The PAGEBURSTACCESSTIME parameter must be set accordingly with GPMCFCLKDIVIDER and
the memory-device internal configuration.
Total access time GPMC_CONFIG5_i[12-8] WRCYCLETIME corresponds to WRACCESSTIME plus the
address hold time from CSn deassertion. In Figure 7-23 the WRCYCLETIME programmed value equals
WRCYCLETIME0 + WRCYCLETIME1. WRCYCLETIME0 and WRCYCLETIME1 delays are not actual
parameters and are only a graphical representation of the full WRCYCLETIME value.
After a write operation, if no other access (read or write) is pending, the data bus keeps the previous
value. See Section 7.1.3.3.9.10.
7.1.3.3.10.3 Asynchronous and Synchronous Accesses in Nonmultiplexed Mode
Page mode is only available in non-multiplexed mode.
• Asynchronous single read operation on a nonmultiplexed device
• Asynchronous single write operation on a nonmultiplexed device
• Asynchronous multiple (page mode) read operation on a nonmultiplexed device
• Synchronous operations on a nonmultiplexed device
296
Memory Subsystem SPRUH73H–October 2011–Revised April 2013
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