NEC PD17062 - Manual (Page 31)

31
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PD17062
5.1.1 Structure of the System Register (SYSREG)
The system register consists of 12 nibbles, located at addresses 74H to 7FH in data memory. The system
register is allocated regardless of the bank. That is, the system register is always located at addresses 74H
to 7FH, regardless of the bank.
Fig. 5-2 shows the structure.
Fig. 5-2 Structure of the System Register
5.1.2 Structure of the Data Buffer (DBF)
The data buffer consists of four nibbles located at addresses 0CH to 0FH of BANK0 in data memory.
Fig. 5-3 shows the structure.
Fig. 5-3 Structure of the Data Buffer
74H 75H 76H 77H 78H 79H 7AH 7BH 7CH 7DH 7EH 7FH Address
Program
status word
(PSWORD)
System register (SYSREG)
Register
(symbol) Address register
(AR)
Window
register
(WR)
Bank
register
(BANK)
Index register (IX)
Data memory row
address pointer
(MP)
General-purpose
register pointer
(RP)
0CH
DBF3
0DH
DBF2
0EH
DBF1
0FH
DBF0
Data buffer (DBF)
Address
Symbol