Filter
Top Products
521
Chapter 31 External Bus
2.External Bus Interface Registers
The function of each bit changes according to the access type (TYP(3-0) bits) setting of the ACR0-7 registers,. A
chip select area determined by either of the following settings becomes the area for normal access or a address/
data multiplex access operation.
The following lists the functions of each AWR0-7 bit for a normal access or address/data multiplex access area.
Since the initial values of registers other than AWR0 are undefined, set them to their initial values before enabling
each area with the CSER register.
The following explains the functions of the bits in the area wait registers (AWR0-7).
TYP3 TYP2 TYP1 TYP0 Access type
00x x
Normal access (asynchronous SRAM, I/O,
and single/page/burst-ROM/FLASH)
01x x
Address data multiplex access (8/16-bit bus
width only)
0000 066A
H
W15 W14 W13 W12 W11 W10 W09 W08
AWR5L 7 6 5 4 3 2 1 0
0000 066B
H
W07 W06 W05 W04 W03 W02 W01 W00
31 30 29 28 27 26 25 24
0000 066C
H
W15 W14 W13 W12 W11 W10 W09 W08
0000 066D
H
W07 W06 W05 W04 W03 W02 W01 W00
0000 066E
H
W15 W14 W13 W12 W11 W10 W09 W08
76543210
0000 066F
H
W07 W06 W05 W04 W03 W02 W01 W00
23 22 21 20 19 18 17 16
15 14 13 12 11 10 9 8
15 14 13 12 11 10 9 8
AWR5H
AWR6L
AWR6H
AWR7L
AWR7H
xxxxxxxx
b
xxxxxxxx
b
xxxxxxxx
b
xxxxxxxx
b
xxxxxxxx
b
xxxxxxxx
b
xxxxxxxx
b
xxxxxxxx
b
xxxxxxxx
b
xxxxxxxx
b
W/R
W/R
W/R
W/R
W/R
xxxxxxxx
b
xxxxxxxx
b
W/R
Initial value
INIT RST Access