Datasheet

REV. 0–16–
ADuC831
Data Pointer (DPTR)
The Data Pointer is made up of three 8-bit registers, named
DPP (page byte), DPH (high byte) and DPL (low byte). These
are used to provide memory addresses for internal and external
code access and external data access. It may be manipulated as
a 16-bit register (DPTR = DPH, DPL), although INC DPTR
instructions will automatically carry over to DPP, or as three
independent 8-bit registers (DPP, DPH, DPL).
The ADuC831 supports dual data pointers. Refer to the Dual
Data Pointer section.
Program Status Word (PSW)
The PSW SFR contains several bits reflecting the current status
of the CPU as detailed in Table I.
SFR Address D0H
Power-On Default Value 00H
Bit Addressable Yes
Table I. PSW SFR Bit Designations
Bit Name Description
7CYCarry Flag
6ACAuxiliary Carry Flag
5F0General-Purpose Flag
4 RS1 Register Bank Select Bits
3 RS0 RS1 RS0 Selected Bank
000
011
102
113
2OVOverflow Flag
1F1General-Purpose Flag
0P Parity Bit
Power Control SFR (PCON)
The PCON SFR contains bits for power-saving options and
general-purpose status flags as shown in Table II.
SFR Address 87H
Power-On Default Value 00H
Bit Addressable No
Table II. PCON SFR Bit Designations
Bit Name Description
7 SMOD Double UART Baud Rate
6 SERIPD I
2
C/SPI Power-Down Interrupt Enable
5 INT0PD INT0 Power-Down Interrupt Enable
4 ALEOFF Disable ALE Output
3 GF1 General-Purpose Flag Bit
2 GF0 General-Purpose Flag Bit
1PD Power-Down Mode Enable
0 IDL Idle Mode Enable