Epson 6200A User Manual
26
EPSON
S1C6200/6200A CORE CPU MANUAL
3 INSTRUCTION SET
3.2 Operands
This section describes the operands used in the instructions.
p
5-bit immediate data or labels 00H to 1FH. Used to specify a destination address.
s
8-bit immediate data or labels 00H to FFH. Used to specify a destination address.
e
8-bit immediate data 00H to FFH.
i
4-bit immediate data 00H to 0FH.
r
2-bit immediate data. See Table 3.2.1.
q
2-bit immediate data. See Table 3.2.1.
The contents of A, B, MX, MY are referenced using r and q as shown in the following table.
Table 3.2.1 Values of r and q
A
B
MX
MY
r
0 or
q
0
0
1
0
1
r
1 or
q
1
0
0
1
1
A
A register
B
B register
XP
XP register---four high-order bits of IX
YP
YP register---four high-order bits of IY
X
XHL register---eight low-order bits of IX
Y
YHL register---eight low-order bits of IY
XH
XH register---four high-order bits of XHL
XL
XL register---four low-order bits of XHL
YH
YH register---four high-order bits of YHL
YL
YL register---four low-order bits of YHL
SP
Stack pointer SP
SPH
Four high-order bits of SP
SPL
Four low-order bits of SP
F
Flag register (IF, DF, ZF, CF)
MX
Data memory location whose address is specified by IX
MY
Data memory location whose address is specified by IY
M
n
Data memory location within the register area (000H to 00FH), specified by immediate data
n (0H to FH)
C
Carry
NC
No carry
Z
Zero
NZ
Not zero
3.3 Flags
1. Carry flag
The carry flag is set if a carry was generated by the previous operation. It is affected by 17 arithmetic
and logical instructions, four flag operations, eight index operation instructions and the POP F instruc-
tion.
and logical instructions, four flag operations, eight index operation instructions and the POP F instruc-
tion.
2. Zero flag
The zero flag is set if a zero occurred in the previous operation. It is affected by 26 arithmetic and logical
instructions, four flag operations, eight index operation instructions and the POP F instruction.
instructions, four flag operations, eight index operation instructions and the POP F instruction.
3. Decimal flag
The decimal flag enables decimal addition and subtraction when set. It is set by SDF or SET F,i and reset
by RDF or RST F,i. It is affected by the POP F instruction.
by RDF or RST F,i. It is affected by the POP F instruction.
4. Interrupt flag
The interrupt flag enables interrupts when set. It is set by EI or SET F,i and reset by DI or RST F,i. It is
affected by the POP F instruction. When an interrupt is generated, the I flag is automatically reset. It is
not automatically set at the end of the interrupt service routine.
affected by the POP F instruction. When an interrupt is generated, the I flag is automatically reset. It is
not automatically set at the end of the interrupt service routine.