SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
The clock runs at 104 MHz (f = 104 MHz; T = 9.615 ns).
Table 12-183 shows the timing parameters (on the memory side) that determine the parameters on the GPMC side.
Table 12-184 shows how to calculate timings for the GPMC using the memory parameters.
Figure 12-102 shows the asynchronous read access.
AC Read Characteristics on the Memory Side | Description | Duration (ns) |
---|---|---|
tCE | Read Access time from nCS low | 80 |
tAAVDS | Address setup time to rising edge of nADV | 3 |
tAVDP | nADV low time | 6 |
tCAS | nCS setup time to nADV | 0 |
tOE | Output enable to output valid | 6 |
tOEZ | Output enable to High-Z | 7 |
Use the following formula to calculate the RdCycleTime parameter for this typical access:
RdCycleTime = RdAccessTime + AccessCompletion = RdAccessTime + 1 clock cycle + tOEZ:
The GPMC requires some hold time to allow the data to be captured correctly and the access to be finished.
Parameter Name on GPMC Side | Formula | Duration (ns) | Number of Clock Cycles (F = 104 MHz) | GPMC Register Configurations |
---|---|---|---|---|
ClkActivationTime | n/a (asynchronous mode) | |||
RdAccessTime | round max (tCE) | 80 | 10 | RDACCESSTIME = 0xA |
PageBurstAccessTime | N/A (single access) | |||
RdCycleTime | RdAccessTime + 1cycle + tOEZ | 96.615 | 12 | RDCYCLETIME = 0xC |
CsOnTime | tCAS | 0 | 0 | CSONTIME = 0x0 |
CsReadOffTime | RdAccessTime + 1 cycle | 89.615 | 11 | CSRDOFFTIME = 0xB |
AdvOnTime | tAAVDS | 3 | 1 | ADVONTIME = 0x1 |
AdvRdOffTime | tAAVDS + tAVDP | 9 | 1 | ADVRDOFFTIME = 0x1 |
OeOnTime | OeOnTime >= AdvRdOffTime (multiplexed mode) | - | 3, for instance | OEONTIME = 0x3 |
OeOffTime | RdAccessTime + 1cycle | 89.615 | 11 | OEOFFTIME = 0xB |