54
µ
PD17062
8. SYSTEM REGISTER (SYSREG)
“System register” is the generic name for those registers directly related to CPU control. System registers
are allocated at addresses 74H-7FH in data memory and can be referenced regardless of the bank specification.
The system register types are as follows:
Address register
Window register
Bank register
Memory pointer enable flag
Index register
Data memory row address pointer
General-purpose register pointer
Program status word
Fig. 8-1 Configuration of System Register
b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0b3b2b1b0
AR3 AR2 AR1 AR0 WR BANK
IXH IXM
MPH MPL
IXL RPH RPL PSW
74H 75H 76H 77H 78H 79H 7AH 7BH 7CH 7DH 7EH 7FH
00000000 00 P0000 0000
B
C
D
C
M
P
C
Y
ZI
X
E
(IX)
Address
Register
Symbol
Bit
Data
Address register
(AR)
System register
Window
register
(WR)
Bank
register
(BANK)
Index register
(IX)
Data memory
row address
pointer
(MP)
General-
purpose
register
pointer
(RP)
Program
status
word
(PSWORD)
M
E(MP)