FM33256B
Document Number: 001-86213 Rev. *C
Page 17 of 39
12h
Serial Number Byte 2
D7
D6
D5
D4
D3
D2
D1
D0
SN.23
SN.22
SN.21
SN.20
SN.19
SN.18
SN.17
SN.16
11h
Serial Number Byte 1
D7
D6
D5
D4
D3
D2
D1
D0
SN.15
SN.14
SN.13
SN.12
SN.11
SN.10
SN.9
SN.8
10h
Serial Number Byte 0
D7
D6
D5
D4
D3
D2
D1
D0
SN.7
SN.6
SN.5
SN.4
SN.3
SN.2
SN.1
SN.0
All serial number bytes are read/write when SNL = ‘0’, read-only when SNL = ‘1’. Nonvolatile.
0Fh
Event Counter Byte 1
D7
D6
D5
D4
D3
D2
D1
D0
EC.15
EC.14
EC.13
EC.12
EC.11
EC.10
EC.9
EC.8
Event Counter Byte 1. Increments on programmed edge event on CNT input. Nonvolatile when NVC = ‘1’,
Battery-backed when NVC = ‘0’, read/write.
0Eh
Event Counter Byte 0
D7
D6
D5
D4
D3
D2
D1
D0
EC.7
EC.6
EC.5
EC.4
EC.3
EC.2
EC.1
EC.0
Event Counter Byte 0. Increments on programmed edge event on CNT input. Nonvolatile when NVC = ‘1’,
Battery-backed when NVC = ‘0’, read/write.
0Dh
Event Counter Control
D7
D6
D5
D4
D3
D2
D1
D0
NVC
-
-
-
RC
WC
POLL
CP
NVC
Nonvolatile/Volatile Counter: Setting this bit to ‘1’ makes the counter nonvolatile and counter operates only when
V
DD
is greater than V
TP
. Setting this bit to ‘0’ makes the counter volatile, which allows counter operation under
V
BAK
or V
DD
power. If the NVC bit is changed, the counter value is not valid. Nonvolatile, read/write.
RC
Read Counter. Setting this bit to ‘1’ takes a snapshot of the two counter bytes allowing the system to read the
values without missing count events. The RC bit will be automatically cleared.
WC
Write Counter. Setting this bit to a ‘1’ allows the user to write the counter bytes. While WC = ‘1’, the counter is
blocked from count events on the CNT pin. The WC bit must be cleared by the user to activate the counter.
POLL
Polled Mode: When POLL = ‘1’, the CNT pin is sampled for 30 µs every 125 ms. If POLL is set, the NVC bit is
internally cleared and the CP bit is set to detect a rising edge. The RTC oscillator must be enabled (OSCEN = ‘0’)
to operate in polled mode. When POLL = ‘0’, CNT pin is continuously active. Nonvolatile, read/write.
CP
The CNT pin detects falling edges when CP = ‘0’, rising edges when CP = ‘1’. Nonvolatile, read/write.
Table 7. Register Description
(continued)
Address
Description