W90P710_05 Datasheet, PDF (40/526 Pages) Winbond – 16/32-bit ARM microcontroller

W90P710
Fig7.2.5 CPU registers Read/Write with external memory
Table 7.2.3 and Table 7.2.4
Using big-endian and word access, Program/Data path between register and external memory
WA = Address whose LSB is 0,4,8,C X = Don’t care
nWBE [3-0] / SDQM [3-0] = A means active and U means inactive
ACCESS
OPERATION
XD WIDTH
Bit Number
CPU Reg Data
SA
Bit Number
SD
Bit Number
ED
XA
nWBE [3-0] /
SDQM [3-0]
Bit Number
XD
Bit Number
Ext. Mem Data
Timing Sequence
Table7.2.3 Word access write operation with Big Endian
WRITE OPERATION (CPU REGISTER Î EXTERNAL MEMORY)
WORD
31 0
ABCD
HALF WORD
31 0
ABCD
BYTE
31 0
ABCD
WA
WA
WA
31 0
ABCD
31 0
AB CD
31 0
ABCD
31 0
15 0
15 0
70
70
70
70
ABCD
AB
CD
A
B
C
D
WA
WA
WA+2
WA
WA+1
WA+2
WA+3
AAAA
31 0
ABCD
31 0
ABCD
XXAA
15 0
AB
15 0
AB
1st write
XXAA
15 0
CD
15 0
CD
2nd write
XXXA
70
A
70
A
1st write
XXXA
70
B
70
B
2nd write
XXXA
70
C
70
C
3rd write
XXXA
70
D
70
D
4th write
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