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CHAPTER 3 SYSTEM CONTROLLER
Preliminary User’s Manual S14767EJ1V0UM00
243
3.4.5 Memory control registers
3.4.5.1 ROM Mode Register (RMMDR)
The ROM Mode Register “RMMDR” is read-write and word aligned 32bit register. RMMDR is used to setup the
PROM/FLASH memory interface. RMMDR is initialized to 0 at reset and contains the following fields:
Bits
Field
Description
1:0
FSM
FLASH/PROM Size Model:
00 = mode1 (4MByte mode)
01 = mode2 (8MByte mode)
10 = reserved
11 = reserved
7:2
Reserved
Hardwired to 0.
8
WM
Write Mask:
0 = Masked. FLASH data is protected from unintentional write.
1 = Not Masked. FLASH data is not protected.
31:9
Reserved
Hardwired to 0.
Remarks 1.
DON’T change the value on the FSM field after setting the value 01 into the FSM field
2.
DON’T set the reserved value to each field in this register.
3.4.5.2 ROM Access Timing Register (RMATR)
The ROM Access Timing Register “RMATR” is read-write and word aligned 32bit register. RMATR is used to set
the access time in the PROM/FLASH interface. RMATR is initialized to 0 at reset and contains the following fields:
Bits
Field
Description
FLASH/PROM Access Timing for Normal ROM:
2:0
FAT
000 = 18clock
001 = 4clock
010 = 6clock
011 = 8clock
100 = 10clock
101 = 12clock
110 = 14clock
111 = 16clock
66MHz:272.4ns
66MHz: 60.6ns
66MHz: 90.9ns
66MHz:121.2ns
66MHz:151.5ns
66MHz:181.8ns
66MHz:212.1ns
66MHz:242.4ns
100MHz:180ns
100MHz: 40ns
100MHz: 60ns
100MHz: 80ns
100MHz:100ns
100MHz:120ns
100MHz:140ns
100MHz:160ns
31:3
Reserved
Hardwired to 0.
Remark
ROM Access Timing is depended on the system clock frequency.