SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
Figure 12-85 shows an asynchronous multiple-read operation on a non-multiplexed device in which two word32 host read accesses to the GPMC are split into one multiple- (page mode of 4 word16) read access to the attached device.
The WAIT signal is active low.
The nCS, nADV, nOE, and DIR signals are controlled in the same way as address/data-multiplexed accesses (see Table 12-197).
When RDACCESSTIME completes, control signal timings are frozen during the multiple data transactions, corresponding to PAGEBURSTACCESSTIME multiplied by the number of remaining data transactions.
Read data is latched at GPMC_CONFIG5_i[20-16] RDACCESSTIME completion time (where i = 0 to 3). The end of the access is defined by the GPMC_CONFIG5_i[4-0] RDCYCLETIME parameter.
During consecutive accesses, the GPMC increments the address after each data read completes.
Delay between successive read data in the page is controlled by the GPMC_CONFIG5_i[27-24] PAGEBURSTACCESSTIME parameter. Depending on the device page length, the GPMC can control device page crossing during a burst request and insert initial RDACCESSTIME latency. Page crossing is possible only with a new burst access, meaning a new initial access phase is initiated.
Total access time RDCYCLETIME corresponds to RDACCESSTIME, plus the address hold time, starting from the nCS deassertion.