4554 Datasheet, PDF (81/138 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4554 Group
MACHINE INSTRUCTIONS (INDEX BY ALPHABET) (continued)
CMCK (Clock select: ceraMic oscillation ClocK)
Instruction
code
D9
D0
Number of Number of Flag CY
1010011010
29A
words
cycles
2
16
1
1
–
Skip condition
–
Operation: Ceramic oscillation circuit selected
Grouping: Other operation
Description: Selects the ceramic oscillation circuit and
stops the on-chip oscillator.
CRCK (Clock select: Rc oscillation ClocK)
Instruction
code
D9
D0
Number of Number of Flag CY
words
cycles
1
0
1
0
0
1
1
0
1
1
2
2
9
B ₁₆
1
1
–
Skip condition
–
Operation: RC oscillation circuit selected
Grouping: Other operation
Description: Selects the RC oscillation circuit and stops
the on-chip oscillator.
DEY (DEcrement register Y)
Instruction
code
D9
D0
Number of Number of Flag CY
0000010111
017
words
cycles
2
16
1
1
–
Skip condition
(Y) = 15
Operation: (Y) ← (Y) – 1
Grouping: RAM addresses
Description: Subtracts 1 from the contents of register Y.
As a result of subtraction, when the con-
tents of register Y is 15, the next instruction
is skipped. When the contents of register Y
is not 15, the next instruction is executed.
DI (Disable Interrupt)
Instruction
code
D9
D0
Number of Number of Flag CY
0000000100
004
words
cycles
2
16
1
1
–
Skip condition
–
Operation: (INTE) ← 0
Grouping: Interrupt control operation
Description: Clears (0) to interrupt enable flag INTE, and
disables the interrupt.
Note:
Interrupt is disabled by executing the DI in-
struction after executing 1 machine cycle.
Rev.3.00 Aug 06, 2004 page 81 of 136
REJ03B0043-0300Z