Datasheet
71M6521DE/DH/FE Data Sheet
Rev 3 Page: 79 of 107
MUX_DIV[1:0]
2002[7:6]
0
0
R/W
The number of states in the input multiplexer.
00- illegal
01- 4 states 10-3 states 11-2 states
OPT_FDC[1:0]
2007[1:0]
0
0
R/W
Selects OPT_TX modulation duty cycle
OPT_FDC
Function
00
50% Low
01
25% Low
10
12.5% Low
11
6.25% Low
OPT_RXDIS
2008[5]
0
0
R/W
OPT_RX can be configured as an analog input to the optical UART
comparator or as a digital input/output, DIO1.
0—OPT_RX, 1—DIO1.
OPT_RXINV
2008[4]
0
0
R/W
Inverts result from OPT_RX comparator when 1. Affects only the
UART input. Has no effect when OPT_RX is used as a DIO input.
OPT_TXE[1,0]
2007[7,6]
00
00
R/W
Configures the OPT_TX output pin.
00—OPT_TX, 01—DIO2, 10—WPULSE, 11—VARPULSE
OPT_TXINV
2008[0]
0
0
R/W
Invert OPT_TX when 1. This inversion occurs before modulation.
OPT_TXMOD
2008[1]
0
0
R/W
Enables modulation of OPT_TX. When OPT_TXMOD is set,
OPT_TX is modulated when it would otherwise have been zero.
The modulation is applied after any inversion caused by
OPT_TXINV.
PLL_OK
2003[6]
0
0
R
Indicates that system power is present and the clock generation PLL
is settled.
PLS_MAXWIDTH
[7:0]
2080[7:0]
FF
FF
R/W
Determines the maximum width of the pulse (low going pulse).
Maximum pulse width is (2*PLS_MAXWIDTH + 1)*T
I
. Where T
I
is
PLS_INTERVAL. If PLS_INTERVAL=0, T
I
is the sample time (397µs).
If 255, disable MAXWIDTH.
PLS_INTERVAL
[7:0]
2081[7:0]
0
0
R/W
If the FIFO is used, PLS_INTERVAL must be set to 81. If
PLS_INTERVAL = 0, the FIFO is not used and pulses are output as
soon as the CE issues them.
PLS_INV
2004[6]
0
0
R/W
Inverts the polarity of WPULSE and VARPULSE. Normally, these
pulses are active low. When inverted, they become active high.
PREBOOT
SFRB2[7]
--
--
R
Indicates that preboot sequence is active.
PRE_SAMPS[1:0]
2001[7:6] 0 0 R/W
The duration of the pre-summer, in samples.
00-42, 01-50, 10-84, 11-100.
RTC_SEC[5:0]
RTC_MIN[5:0]
RTC_HR[4:0]
RTC_DAY[2:0]
RTC_DATE[4:0]
RTC_MO[3:0]
RTC_YR[7:0]
2015
2016
2017
2018
2019
201A
201B
--
--
--
--
--
--
--
--
--
--
--
--
--
--
R/W
R/W
R/W
R/W
R/W
R/W
R/W
The RTC interface. These are the ‘year’, ‘month’, ‘day’, ‘hour’,
‘minute’ and ‘second’ parameters of the RTC. The RTC is set by
writing to these registers. Year 00 and all others divisible by 4 are
defined as leap years.
SEC 00 to 59
MIN 00 to 59
HR 00 to 23 (00=Midnight)
DAY 01 to 07 (01=Sunday)
DATE 01 to 31
MO 01 to 12
YR 00 to 99
Each write to one of these registers must be preceded by a write to
201F (WE).