4509 Datasheet, PDF (91/142 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4509 Group
MACHINE INSTRUCTIONS (INDEX BY ALPHABET) (continued)
RC (Reset Carry flag)
Instruction
code
D9
D0
Number of Number of Flag CY
0000000110
006
words
cycles
2
16
1
1
0
Skip condition
–
Operation: (CY) ← 0
Grouping: Arithmetic operation
Description: Clears (0) to carry flag CY.
RD (Reset port D specified by register Y)
Instruction
code
D9
D0
Number of Number of Flag CY
0000010100
014
words
cycles
2
16
1
1
–
Skip condition
–
Operation:
(D(Y)) ← 0
However,
(Y) = 0 to 5
Grouping: Input/Output operation
Description: Clears (0) to a bit of port D specified by register Y.
Note:
(Y) = 0 to 5.
Do not execute this instruction if values ex-
cept above are set to register Y.
RT (ReTurn from subroutine)
Instruction
code
D9
D0
Number of Number of Flag CY
0001000100
044
words
cycles
2
16
1
2
–
Skip condition
–
Operation:
(PC) ← (SK(SP))
(SP) ← (SP) – 1
Grouping: Return operation
Description: Returns from subroutine to the routine
called the subroutine.
RTI (ReTurn from Interrupt)
Instruction
code
D9
D0
Number of Number of Flag CY
0001000110
046
words
cycles
2
16
1
1
–
Skip condition
–
Operation:
(PC) ← (SK(SP))
(SP) ← (SP) – 1
Grouping: Return operation
Description: Returns from interrupt service routine to
main routine.
Returns each value of data pointer (X, Y, Z),
carry flag, skip status, NOP mode status by
the continuous description of the LA/LXY in-
struction, register A and register B to the
states just before interrupt.
Rev.1.02 2006.12.22 page 91 of 140
REJ03B0147-0102