Registers
The 8032 has several registers; these are the Pro-
gram Counter (PC), Accumulator (A), B Register
(B), the Stack Pointer (SP), the Program Status
Word (PSW), General purpose registers (R0 to
R7), and DPTR (Data Pointer register).
Accumulator. The Accumulator is the 8-bit gen-
eral purpose register, used for data operation such
as transfer, temporary saving, and conditional
tests. The Accumulator can be used as a 16-bit
register with B Register as shown in Figure 6.
B Register. The B Register is the 8-bit general
purpose register, used for an arithmetic operation
such as multiply, division with the Accumulator
(see Figure 7).
Stack Pointer. The Stack Pointer Register is 8
bits wide. It is incremented before data is stored
during PUSH and CALL executions. While the
stack may reside anywhere in on-chip RAM, the
Stack Pointer is initialized to 07h after reset. This
causes the stack to begin at location 08h (see Fig-
ure 8).
Program Counter. The Program Counter is a 16-
bit wide which consists of two 8-bit registers, PCH
and PCL. This counter indicates the address of the
next instruction to be executed. In RESET state,
the program counter has reset routine address
(PCH:00h, PCL:00h).
Program Status Word. The
Program
Status
Word (PSW) contains several bits that reflect the
current state of the CPU and select Internal RAM
(00h to 1Fh: Bank0 to Bank3). The PSW is de-
scribed in Figure 9, page 19. It contains the Carry
Flag, the Auxiliary Carry Flag, the Half Carry (for
BCD operation), the general purpose flag, the
Register Bank Select Flags, the Overflow Flag,
and Parity Flag.
[Carry Flag, CY]. This flag stores any carry or not
borrow from the ALU of CPU after an arithmetic
operation and is also changed by the Shift Instruc-
tion or Rotate Instruction.
[Auxiliary Carry Flag, AC]. After operation, this is
set when there is a carry from Bit 3 of ALU or there
is no borrow from Bit 4 of ALU.
[Register Bank Select Flags, RS0, RS1]. This flags
select
one
of
four
bank(00~07H:bank0,
08~0Fh:bank1, 10~17h:bank2, 17~1Fh:bank3) in
Internal RAM.
[Overflow Flag, OV]. This flag is set to
