Toshiba H1 Series - Manual (Page 587)

TMP92CZ26A
92CZ26A-584
(2) Timing of INTRTC and Clock data
When time is read by interrupt, read clock data within 0.5s(s) after generating
interrupt. This is because count up of clock data occurs by rising edge of 1Hz pulse
cycle.
Figure 3.21.3 Timing of INTRTC and Clock data
56 57 58 59 0 1 2 3 4
ALARM
INTRTC
1s counter
(Internal signal)
1s count UP
(Internal signal)