Renesas Hitachi H8S/2194 Series Hardware Manual page 665

Field signal
VD
Selected VD
(OD/EV=0)
Value set in reference
period register 1 (RFD)
Counter
Value set in REF30
counter register (RFC)
Toggle mask
Counter mask
(clear signal mask)
REF30
REF30P
HSW
Drum phase counter
Figure 28.10 Generation of Reference Signal in Record Mode (V Dropped Out)
Rev. 2.0, 11/00, page 638 of 1037
Drop-out of V
Cleared
Masking
period
About 75% About 75%
Masking
period
About
About 75%
25%
Sampling
Cleared
About 75%
T
Sampling
Cleared
Sampling