H83657 Datasheet, PDF (243/453 Pages) Renesas Technology Corp – single-chip microcomputers

Bits 2 to 0: Clock select (CKS2 to CKS 0)
When CKS3 = 0, bits 2 to 0 select the prescaler division ratio and the serial clock cycle.
Bit 2
CKS2
0
0
0
0
1
1
1
1
Bit 1
CKS1
0
0
1
1
0
0
1
1
Bit 0
CKS0
0
1
0
1
0
1
0
1
Prescaler Division
ø/1024 (initial value)
ø/256
ø/64
ø/32
ø/16
ø/8
ø/4
ø/2
Serial Clock Cycle
ø = 5 MHz
ø = 2.5 MHz
204.8 µs
409.6 µs
51.2 µs
102.4 µs
12.8 µs
25.6 µs
6.4 µs
12.8 µs
3.2 µs
6.4 µs
1.6 µs
3.2 µs
0.8 µs
1.6 µs
—
0.8 µs
235