z89176 ZiLOG Semiconductor, z89176 Datasheet - Page 43

• Manufacturer Part Number: z89176
• Description: Voice Processing Controllers
• Manufacturer: ZiLOG Semiconductor

Zilog
Half-Second Timer Status Register (HSEC). The half-
second timer status register (Figure 30) is a free-running
timer clocked by the external 32.768 kHz crystal. In normal
operation mode, every half-second, the timer will time-out
and set bit 0 (D0) of the HSEC register to 1. The user can
reset this bit for real timing. In Stop mode, this timer can be
used as a Stop-Mode Recovery source. Every half-sec-
ond, the timer will recover the Stop mode and bit 0 of the
HSEC register will be set to 1. Therefore, in Stop mode,
the user can keep real time.
DS97TAD0100
WDTMR (F) 0F
D7 D6 D5 D4 D3 D2 D1 D0
* Default setting after RESET
Figure 28. Watch-Dog Timer Mode Register
P R E L I M I N A R Y
WDT TAP
00
01*
10
11
WDT During HALT
0 OFF
1 ON*
WDT During STOP
0 OFF
1 ON*
XTAL1/INT RC Select for WDT
0 On-Board RC
1 XTAL
W No effect
R Always "1"
HSEC (F) 0E
D7 D6 D5 D4 D3 D2 D1 D0
Figure 29. Half-Second Timer Status Register
INT RC OSC
100 ms
15 ms
25 ms
5 ms
EXTERNAL CLOCK
Voice Processing Controllers
R 1 Half second time-out
W 1 No effect
Reserved R "0"
4096 Tpc
1024 Tpc
512 Tpc
256 Tpc
0 No time-out
0 RESET the half second timer bit
W No effect
Z89175/Z89176
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