SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
The examples in Section 12.3.4.3.12.1.2.1 through Section 12.3.4.3.12.1.2.3 are based on a clock rate of 104 MHz. See the device-specific Datasheet for the maximum frequency appropriate for this device and the memory datasheet for the maximum frequency for the particular memory device.
The clock runs at 104 MHz (f = 104 MHz; T = 9.615 ns).
Table 12-181 shows the timing parameters (on the memory side) that determine the parameters on the GPMC side.
Table 12-182 shows how to calculate timings for the GPMC using the memory parameters.
Figure 12-101 shows the synchronous burst read access.
AC Read Characteristics on the Memory Side | Description | Duration (ns) |
---|---|---|
tCES | nCS setup time to clock | 0 |
tACS | Address setup time to clock | 3 |
tIACC | Synchronous access time | 80 |
tBACC | Burst access time valid clock to output delay | 5.2 |
tCEZ | Chip-select to High-Z | 7 |
tOEZ | Output enable to High-Z | 7 |
tAVC | nADV setup time | 6 |
tAVD | nAVD pulse | 6 |
tACH | Address hold time from clock | 3 |
The following terms, which describe the timing interface between the controller and its attached device, are used to calculate the timing parameters on the GPMC side:
Parameter Name on GPMC Side | Formula | Duration (ns) | Number of Clock Cycles (F = 104 MHz) | GPMC Register Configurations |
---|---|---|---|---|
GPMC FCLK Divider | – | – | – | GPMCFCLKDIVIDER = 0x0 |
ClkActivation Time | min (tCES, tACS) | 3 | 1 | CLKACTIVATIONTIME = 0x1 |
RdAccessTime | roundmax (ClkActivationTime + tIACC + DataSetupTime) | 94.03: (9.615 + 80 + 4.415) | 10: roundmax (94.03 / 9.615) | RDACCESSTIME = 0xA |
PageBurst RdAccessTime | roundmax (tBACC) | roundmax (5.2) | 1 | PAGEBURSTACCESSTIME = 0x1 |
RdCycleTime | RdAccess time + max (tCEZ, tOEZ) | 101.03: (94.03 + 7) | 11 | RDCYCLETIME = 0xB |
CsOnTime | tCES | 0 | 0 | CSONTIME = 0x0 |
CsReadOffTime | RdCycleTime | - | 11 | CSRDOFFTIME = 0xB |
AdvOnTime | tAVC (1) | 0 | 0 | ADVONTIME = 0x0 |
AdvRdOffTime | tAVD + tAVC (2) | 12 | 2 | ADVRDOFFTIME = 0x2 |
OeOnTime (3) | (ClkActivationTime + tACH) < OeOnTime (ClkActivationTime + tIACC) | – | 3, for instance | OEONTIME = 0x3 |
OeOffTime | RdCycleTime | – | 11 | OEOFFTIME = 0xB |