GPMC
7.1.3.9.1.3 Asynchronous NOR Flash Timing Parameters Formulas
This section lists all formulas to use in order to calculate asynchronous NOR timing parameters. This is
the case when [11-10] DEVICETYPE = 0x0 and when READTYPE or WRITETYPE are set to
asynchronous mode.
Table 7-44. Asynchronous NOR Formulas Description Table
Configuration
Unit
Description
Parameter
A
ns
Pulse duration - GPMC_CSn low
B
ns
Delay time - GPMC_CSn valid to GPMC_ADVn_ALE invalid
C
ns
Delay time - GPMC_CSn valid to GPMC_OEn invalid (single read)
D
ns
Pulse duration - address bus valid - 2nd, 3rd and 4th accesses
E
ns
Delay time - GPMC_CSn valid to GPMC_WEn valid
F
ns
Delay time - GPMC_CSn valid to GPMC_WEn invalid
G
ns
Address invalid duration between 2 successive R/W accesses
H
ns
Setup time - read data valid before GPMC_OEn high
I
ns
Delay time - GPMC_CSn valid to GPMC_OEn invalid (burst read)
J
ns
Delay time - address bus valid to GPMC_CSn valid
Delay time - data bus valid to GPMC_CSn valid
Delay time - GPMC_BE0n_CLE/GPMC_BE1n valid to GPMC_CSn valid
K
ns
Delay time - GPMC_CSn valid to GPMC_ADVn_ALE valid
L
ns
Delay time - GPMC_CSn valid to GPMC_OEn valid
M
ns
Delay time - GPMC_CS valid to first data latching edge
N
ns
Pulse duration - GPMC_BE0n_CLE/GPMC_BE1n valid time
O
ns
Delay time - GPMC_CSn valid to GPMC_ADVn_ALE valid
The configuration parameters are calculated through the following formulas. Note that these formulas are
not exhaustive.
GPMC_CSn low pulse:
For single read: A = (CSRDOFFTIME - CSONTIME) * (TIMEPARAGRANU 1) *
GPMC_FCLK period
For burst read: A = (CSRDOFFTIME - CS (N - 1) * PAGEBURSTACCESSTIME) *
(TIMEPARAGRANU 1) * GPMC_FCLK period, where N = page burst access number
For single write: A = (CSWROFFTIME - CSONTIME) * (TIMEPARAGRANU 1) *
GPMC_FCLK period
For burst write: A = (CSWROFFTIME - CS (N - 1) * PAGEBURSTACCESSTIME) *
(TIMEPARAGRANU 1) * GPMC_FCLK period, where N = page burst access number
GPMC_CSn valid to GPMC_ADVn_ALE invalid delay:
For reading: B = ((ADVRDOFFTIME - CSONTIME) * (TIMEPARAGRANU 1) + 0.5 *
(ADVEXTRADELAY - CSEXTRADELAY)) * GPMC_FCLK period
For writing: B = ((ADVWROFFTIME - CSONTIME) * (TIMEPARAGRANU 1) + 0.5 *
(ADVEXTRADELAY - CSEXTRADELAY)) * GPMC_FCLK period
C = ((OEOFFTIME - CSONTIME) * (TIMEPARAGRANU 1) + 0.5 * (OEEXTRADELAY -
CSEXTRADELAY)) * GPMC_FCLK period
D = PAGEBURSTACCESSTIME * (TIMEPARAGRANU 1) * GPMC_FCLK period
E = ((WEONTIME - CSONTIME) * (TIMEPARAGRANU 1) + 0.5 * (WEEXTRADELAY -
CSEXTRADELAY)) * GPMC_FCLK period
F = ((WEOFFTIME - CSONTIME) * (TIMEPARAGRANU 1) + 0.5 * (WEEXTRADELAY -
CSEXTRADELAY)) * GPMC_FCLK period
G = CYCLE2CYCLEDELAY * GPMC_FCLK period
353
SPRUH73H – October 2011 – Revised April 2013
Memory Subsystem
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