Duty Measurement Control Register 1 (Twcr1) - Renesas H8S/2437 Hardware Manual

14.3.3

Duty Measurement Control Register 1 (TWCR1)

TWCR1 controls the free-running counter (TWCNT) and selects the TWCNT input clock and an
external event signal whose duty is to be measured.
Bit Bit Name Initial Value
7 FRC 0

6 0
5 CKS2 0
4 CKS1 0
3 CKS0 0
2 IS2 0
1 IS1 0
0 IS0 0
R/W Description
R/W Free-Running Counter
When 1 is written to this bit, TWCNT operates as a
free-running counter regardless of the state of the START
bit.
0: Duty measurement operation
1: Free-running counter operation
R/W Reserved
R/W Clock Select 2 to 0
R/W Select the clock input to TWCNT.
000: Count on internal clock φ
R/W
001: Count on internal clock φ/2
010: Count on internal clock φ/4
011: Count on internal clock φ/8
100: Count on internal clock φ/32
101: Count on internal clock φ/2048
110: Count on internal clock φ/32768
111: Count on internal clock φ/65536
R/W Input Select 2 to 0
R/W Select the external event signal whose duty is to be
measured.
R/W
000: Measure the duty of HSYNCI_0
001: Measure the duty of HSYNCI_1
010: Measure the duty of CSYNCI_0
011: Measure the duty of CSYNCI_1
100: Measure the duty of HFBACKI
101: Measure the duty of VFBACKI
110: Measure the duty of VSYNCI_0
111: Measure the duty of VSYNCI_1
Rev. 1.00, 09/03, page 403 of 704