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8XC196NT USER'S MANUAL
WSR
WSR
The window selection register (WSR) has two functions. One bit enables and disables the bus-hold
protocol. The remaining bits select windows. Windows map sections of RAM into the upper section of
the lower register file, in 32-, 64-, or 128-byte increments. PUSHA saves this register on the stack and
POPA restores it.
7
HLDEN
W6
Bit
Bit
Number
Mnemonic
7
HLDEN
6:0
W6:0
Table C-17. WSR Settings and Direct Addresses for Windowable SFRs
Register Mnemonic
AD_COMMAND
AD_RESULT
AD_TEST
AD_TIME
COMP0_CON
†
COMP0_TIME
COMP1_CON
†
COMP1_TIME
†
EPA_MASK
EPA_MASK1
†
Must be addressed as a word.
C-66
W5
W4
HOLD#/HLDA# Protocol Enable
This bit enables and disables the bus-hold protocol (see Chapter 14,
"Interfacing with External Memory"). It has no effect on windowing.
1 = enable
0 = disable
Window Selection:
These bits specify the window size and window number:
6 5 4 3 2 1 0
1 x x x x x x 32-byte window; W5:0 = window number
0 1 x x x x x 64-byte window; W4:0 = window number
0 0 1 x x x x 128-byte window; W3:0 = window number
32-Byte Windows
(00E0–00FFH)
Memory
Location
Direct
WSR
Address
1FACH
7DH
00ECH
1FAAH
7DH
00EAH
1FAEH
7DH
00EEH
1FAFH
7DH
00EFH
1F88H
7CH
00E8H
1F8AH
7CH
00EAH
1F8CH
7CH
00ECH
1F8EH
7CH
00EEH
1FA0H
7DH
00E0H
1FA4H
7DH
00E4H
Address:
Reset State:
W3
W2
Function
64-Byte Windows
(00C0–00FFH)
Direct
WSR
Address
3EH
00ECH
3EH
00EAH
3EH
00EEH
3EH
00EFH
3EH
00C8H
3EH
00CAH
3EH
00CCH
3EH
00CEH
3EH
00E0H
3EH
00E4H
14H
00H
0
W1
W0
128-Byte Windows
(0080–00FFH)
Direct
WSR
Address
1FH
00ACH
1FH
00AAH
1FH
00AEH
1FH
00AFH
1FH
0088H
1FH
008AH
1FH
008CH
1FH
008EH
1FH
00A0H
1FH
00A4H
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