DS21354/DS21554 3.3V/5V E1 Single-Chip Transceivers
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4. PARALLEL PORT
The DS21354/DS21554 are controlled through either a nonmultiplexed (MUX = 0) or a multiplexed
(MUX = 1) bus by an external microcontroller or microprocessor. The device can operate with either Intel
or Motorola bus timing configurations. If the BTS pin is tied low, Intel timing is selected; if tied high,
Motorola timing is selected. All Motorola bus signals are listed in parentheses (). See the timing diagrams
in Section
for more details.
4.1.
Register Map
Table 4-1. Register Map Sorted by Address
ADDRESS TYPE
REGISTER
NAME
00
R
BPV or Code Violation Count 1
VCR1
01
R
BPV or Code Violation Count 2
VCR2
02
R
CRC4 Error Count 1/FAS Error Count 1
CRCCR1
03
R
CRC4 Error Count 2
CRCCR2
04 R
E-Bit
Count
1/FAS
Error Count 2
EBCR1
05 R
E-Bit
Count
2
EBCR2
06 R/W
Status
1
SR1
07
R/W
Status 2
SR2
08 R/W
Receive
Information
RIR
09
—
Not used
(set to 00h)
0A
—
Not used
(set to 00h)
0B
—
Not used
(set to 00h)
0C
—
Not used
(set to 00h)
0D
—
Not used
(set to 00h)
0E
—
Not used
(set to 00h)
0F R
Device
ID
IDR
10
R/W
Receive Control 1
RCR1
11
R/W
Receive Control 2
RCR2
12
R/W
Transmit Control 1
TCR1
13
R/W
Transmit Control 2
TCR2
14
R/W
Common Control 1
CCR1
15
R/W
Test 1
TEST1 (set to 00h)
16 R/W
Interrupt
Mask
1
IMR1
17 R/W
Interrupt
Mask
2
IMR2
18
R/W
Line Interface Control Register
LICR
19
R/W
Test 2
TEST2 (set to 00h)
1A
R/W
Common Control 2
CCR2
1B
R/W
Common Control 3
CCR3
1C
R/W
Transmit Sa Bit Control
TSaCR
1D
R/W
Common Control 6
CCR6
1E R
Synchronizer
Status
SSR
1F
R
Receive Non-Align Frame
RNAF
20
R/W
Transmit Align Frame
TAF
21
R/W
Transmit Non-Align Frame
TNAF
22
R/W
Transmit Channel Blocking 1
TCBR1
23
R/W
Transmit Channel Blocking 2
TCBR2
24
R/W
Transmit Channel Blocking 3
TCBR3