GPMC
The configuration parameters are calculated through the following formulas.
For single read accesses:
A = (CSRDOFFTIME - CSONTIME) * (TIMEPARAGRANU 1) * GPMC_FCLK period
C = RDCYCLETIME * (TIMEPARAGRANU 1) * GPMC_FCLK period
D = (RDCYCLETIME - ACCESSTIME) * GPMC_FCLK period
E = (CSRDOFFTIME - ACCESSTIME) * GPMC_FCLK period
For burst read accesses (where n is the page burst access number):
A = (CSRDOFFTIME - CS (n - 1) * PAGEBURSTACCESSTIME) *
(TIMEPARAGRANU 1) * GPMC_FCLK period
C = (RDCYC (n - 1) * PAGEBURSTACCESSTIME) * (TIMEPARAGRANU 1) *
GPMC_FCLK period
D = (RDCYCLETIME - (ACCE (n - 1) * PAGEBURSTACCESSTIME) * GPMC_FCLK period
E = (CSRDOFFTIME - (ACCE (n - 1) * PAGEBURSTACCESSTIME) * GPMC_FCLK period
For burst write accesses (where n is the page burst access number):
A = (CSWROFFTIME - CS (n - 1) * PAGEBURSTACCESSTIME) *
(TIMEPARAGRANU 1) * GPMC_FCLK period
C = (WRCYC (n - 1) * PAGEBURSTACCESSTIME) * (TIMEPARAGRANU 1) *
GPMC_FCLK period
D = (WRCYCLETIME - (ACCE (n - 1) * PAGEBURSTACCESSTIME) * GPMC_FCLK period
E = (CSWROFFTIME - (ACCE (n - 1) * PAGEBURSTACCESSTIME) * GPMC_FCLK period
For all accesses:
For CSn falling edge (CSn activated):
•
Case where GPMC_CONFIG1_i[1-0] GPMCFCLKDIVIDER = 0x0
F = 0.5 * CSEXTRADELAY * GPMC_FCLK period
•
Case where GPMCFCLKDIVIDER = 0x1
F = 0.5 * CSEXTRADELAY * GPMC_FCLK period, when (CLKACTIVATIONTIME and CSONTIME are
odd) or (CLKACTIVATIONTIME and CSONTIME are even)
F = (1 + 0.5 * CSEXTRADELAY) * GPMC_FCLK period otherwise
•
Case where GPMCFCLKDIVIDER = 0x2
F = 0.5 * CSEXTRADELAY * GPMC_FCLK period, when (CSONTIME - CLKACTIVATIONTIME) is a
multiple of 3
F = (1 + 0.5 * CSEXTRADELAY) * GPMC_FCLK period, when (CSONTIME - CLKACTIVATIONTIME -
1) is a multiple of 3
F = (2 + 0.5 * CSEXTRADELAY) * GPMC_FCLK period, when (CSONTIME - CLKACTIVATIONTIME -
2) is a multiple of 3
For CSn rising edge (CSn de-activated) in reading mode:
•
Case where GPMC_CONFIG1_i[1-0] GPMCFCLKDIVIDER = 0x0
F = 0.5 * CSEXTRADELAY * GPMC_FCLK period
•
Case where GPMCFCLKDIVIDER = 0x1
F = 0.5 * CSEXTRADELAY * GPMC_FCLK period, when (CLKACTIVATIONTIME and CSRDOFFTIME
are odd) or (CLKACTIVATIONTIME and CSRDOFFTIME are even)
F = (1 + 0.5 * CSEXTRADELAY) * GPMC_FCLK period otherwise
•
Case where GPMCFCLKDIVIDER = 0x2
F = 0.5 * CSEXTRADELAY * GPMC_FCLK period, when (CSRDOFFTIME - CLKACTIVATIONTIME) is
a multiple of 3
F = (1 + 0.5 * CSEXTRADELAY) * GPMC_FCLK period, when (CSRDOFFTIME -
CLKACTIVATIONTIME - 1) is a multiple of 3
F = (2 + 0.5 * CSEXTRADELAY) * GPMC_FCLK period, when (CSRDOFFTIME -
348
Memory Subsystem
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated