SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
This section lists all the formulas to calculate asynchronous NOR timing parameters. This is the case when GPMC_CONFIG1_i[11-10] DEVICETYPE = 0x0 and when READTYPE or WRITETYPE are set to asynchronous mode. Table 12-4176 describes the asynchronous NOR formulas.
Configuration Parameter | Unit | Description |
---|---|---|
A | ns | Pulse duration – nCS low |
B | ns | Delay time – nCS valid to nADV/ALE invalid |
C | ns | Delay time – nCS valid to nOE/nRE invalid (single read) |
D | ns | Pulse duration – address bus valid - 2nd, 3rd and 4th accesses |
E | ns | Delay time – nCS valid to nWE valid |
F | ns | Delay time – nCS valid to nWE invalid |
G | ns | Address invalid duration between two successive R/W accesses |
H | ns | Setup time – read data valid before nOE/nRE high |
I | ns | Delay time – nCS valid to nOE/nRE invalid (burst read) |
J | ns | Delay time – address bus valid to nCS valid |
Delay time – data bus valid to nCS valid | ||
Delay time – nBE0 / nBE1 valid to nCS valid | ||
K | ns | Delay time – nCS valid to nADV/ALE valid |
L | ns | Delay time – nCS valid to nOE/nRE valid |
M | ns | Delay time – nCS valid to first data latching edge |
N | ns | Pulse duration – nBE0 / nBE1 valid time |
O | ns | Delay time – nCS valid to nADV/ALE valid |
The configuration parameters are calculated through the following formulas. These formulas are not exhaustive. For more information, see the device-specific Datasheet.
Figure 12-2124 shows a simplified example of an asynchronous NOR single write where formulas are associated with signal waves.
Write multiple access is not supported in asynchronous mode. If WRITEMULTIPLE is enabled with WRITETYPE as asynchronous, the GPMC processes single asynchronous accesses.