CS61304A Cirrus Logic, Inc., CS61304A Datasheet - Page 17

• Manufacturer Part Number: CS61304A
• Description: T1-E1 Line Interface Unit for CPE-ISDN PRI
• Manufacturer: Cirrus Logic, Inc.

The data register, shown in Table 10, can be writ-
ten to the serial port. Data is input on the eight
clock cycles immediately following the ad-
dress/command byte. Bits 0 and 1 are used to
clear an interrupt issued from the INT pin, which
occurs in response to a loss of signal or a problem
with the output driver.
Writing a "1" to either "Clear LOS" or "Clear
DPM" over the serial interface has three effects:
Writing a "0" to either "Clear LOS" or "Clear
DPM" enables the corresponding interrupt for
LOS or DPM.
Output data from the serial interface is presented
as shown in Tables 11 and 12. Bits 2, 3 and 4 can
be read to verify line length selection. Bits 5, 6
and 7 must be decoded. Codes 101, 110 and 111
(Bits 5, 6 and 7) indicate intermittent loss of sig-
nal and/or driver problems.
SDO goes to a high impedance state when not in
use. SDO and SDI may be tied together in appli-
cations where the host processor has a
bi-directional I/O port.
DS156PP2
LSB: first bit in
MSB: last bit in 7
1) The current interrupt on the serial interface
2) Output data bits 5, 6 and 7 will be reset as
3) Future interrupts for the corresponding LOS
will be cleared. (Note that simply reading
the register bits will not clear the inter-
rupt).
appropriate.
or DPM will be prevented from occurring.
Table 10. Input Data Register
0 clr LOS Clear Loss of Signal
1 clr DPM Clear Driver Performance Monitor
2
3
4
5 RLOOP Remote Loopback
6 LLOOP Local Loopback
LEN0 Bit 0 - Line Length Select
LEN1 Bit 1 - Line Length Select
LEN2 Bit 2 - Line Lenght Select
TAOS Transmit All Ones Select
LSB: first bit in
5 6 7
0 0 0 Reset has occurred or no program input.
0 0 1 TAOS in effect.
0 1 0 LLOOP in effect.
0 1 1 TAOS/LLOOP in effect.
1 0 0 RLOOP in effect
1 0 1 DPM changed state since last "clear DPM"
1 1 0 LOS changed state since last "clear LOS"
1 1 1 LOS and DPM have changed state since
Bits
Table 12. Coding for Serial Output bits 5,6,7
occured.
occured.
last "clear LOS" and "clear DPM".
Table 11. Output Data Bits 0 - 4
0
1
2
3
4
LEN0 Bit 0 - Line Length Select
LEN1 Bit 1 - Line Length Select
LEN2 Bit 2 - Line Lenght Select
DPM
LOS
Loss of Signal
Driver Performance Monitor
Status
CS61304A
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