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Chapter 11 Memory Controller
8.Explanations of Registers
FLASH access cycle waveform
Figure 8-1 shows the example of a FLASH access cycle. In the FMWT register the three parts of the FLASH timing
tATD, tALEH, tEQ and tWTC can be configured independently. The table below lists the configuration values for
this example.
The resulting FLASH access cycle (tRC) time is 7 cycles (WTC+1).
BIT[2:0]: PS[2:0] - Page size definition for Page Mode FLASH
PS is set to 0 after reset. Page Mode FLASH is disabled by default.
This setting defines the page size to 2^PS in number of bytes.
E.g. for Am29PL320D/MBM29PL3200 with a page size of 16 byte the value of PS has to be set to 4.
(Embedded FLASH memories on MB91460 series do not support page mode)
Symbol Length Setup
tATD 1.5 cycles ATD=2
tALEH 1.5 cycles ALEH=2
tEQ 3 cycles EQ=5
tWTC 6 cycles WTC=6
flash_start
FMA
ATDIN
EQIN
flash_wait
DO
tRC
tWTC
tATD tEQtALEH
Figure 8-1 Timing of a FLASH access cycle