Abstract: Application Note 349 provides a detailed list of the features included in the DS2152L that are not included in the DS2151Q T1 single chip transceiver (SCT). All of the original features of the DS2151Q have been retained. All software and hardware for the DS2151Q may be used with the DS2152L with minimal effort.
Introduction
This application note highlights the differences between the DS2152L and the DS2151Q T1 Single Chip
Transceivers. The DS2152L is a superset of the DS2151Q. All of the original features of the DS2151Q
have been retained and software created for the DS2151Q is transferable to the DS2152L with minimal
effort.
Additional Functionality
New Features
Section
Option for non-multiplexed bus operation
1 & 2
Crystal-less jitter attenuation
14
Additional hardware signaling capability
Receive signaling reinsertion to a backplane multiframe sync
Availability of signaling in a separate PCM data stream
Signaling freezing>
Interrupt generated on change of signaling data
7.2 & 9
Per-channel code insertion in both transmit and receive paths
8
Full HDLC controller for the FDL with 16-byte buffers in both transmit and receive paths
11
RCL, RLOS, RRA, and RAIS alarms now interrupt on change of state
4
8.192 MHz clock synthesizer
1
Per-channel loopback capability
1
Addition of hardware pins to indicate carrier loss and signaling freeze
1
Line interface function can be completely decoupled from the framer/formatter to allow:
Interface to optical, HDSL, and other NRZ interfaces
Be able to tap the transmit and receive bipolar data streams for monitoring purposes
Be able to corrupt data and insert framing errors, CRC errors, etc.
1
Transmit and receive elastic stores now have independent backplane clocks
1
Ability to monitor DS0 channel in both the transmit and receive paths
6
Access to the data stream in between the framer/formatter and the elastic stores
1
AIS generation in the line interface that is independent of loopbacks
1 & 3
Ability to calculate and check CRC6 according to the Japanese standard
3
Ability to pass the F-Bit through the elastic stores in the 2.048 MHz backplane mode
3 & 15
Programmable in-band loop code generation and detection
12
Device identification register
3
Changes in Register Definitions
When implementing the new features of the DS2152L, a priority was placed on preserving the DS2151Qs
register map to facilitate code migration from existing DS2151Q designs. This section highlights register
additions and differences found in the DS2152L.
New Feature Register Usage
Highlights specific registers containing bit locations related to new features. Each item can be found in
the data sheet under the listed sections.
Full HDLC & BOC Controller For FDL Support (Section 11.1)
Interrupt On Change of State for RCL, RLOS, RRA, RAIS(Section 4.0)
Register
Description
SR2
Status Register 2
IMR2
Interrupt Mask Register 2
Bit Assignment Changes Within Existing Registers
Highlights bit locations in the DS2152L which have changed from the DS2151Q.
Register
Bit No.
DS2151Q Symbol
DS2151Q Description
DS2152L Symbol
DA2152L Description
TCR1
2
TLINK
TLINK Select
TFDLS
TFDL Select
TCR2
0
B7ZS
Bit 7 Zero Suppression Enable
TB7ZS
Transmit Side Bit 7 Zero Suppression Enable
CCR1
3
SCLKM
SYSCLK Mode Select
RSCLKM
RSYSCLK Mode Select
CCR1
4
RLB
Remote Loop Back
TSCLKM
TSYSCLK Mode Select
CCR1
6
LLB
Local Loop Back
ODF
Output Data Format
CCR3
0
LIRST
Line Interface Reset
N/A
Not Assigned
CCR3
1
TLU
Transmit Loop Up
TLOOP
Transmit Loop Up Enable
CCR3
2
TLD
Transmit Loop Down
ECUS
Error Counter Update Select
CCR3
5
P16F
Function of Pin 16
RLOSF
Function of the RLOS/LOTC Output
RIR2
2
JALT
Jitter Attenuator Limit Trip
RBLC
Receive Blue Alarm Clear
RIR2
6
RL0
Receive Level Bit 0
LRCLC
Line Interface Receive Carrier Loss Clear
RIR2
7
RL1
Receive Level Bit 1
RLOSC
Receive Loss of SYNC Clear
SR1
1
RCL
Receive Carrier Loss
LRCL
Line Interface Receive Carrier Loss
SR2
0
N/A
Not Assigned
RSC
Receive Signaling Change
IMR1
1
RCL
Receive Carrier Loss
LRCL
Line Interface Receive Carrier Loss
IMR2
0
N/A
Not Assigned
RSC
Receive Signaling Change
Register Bit Moves
Function
DS2151Q Location
DS2152L Location
JALT
RIR2.2
RIR3.5
LIRST
CCR3.0
CCR6.7
LLB
CCR1.6
CCR5.6
RL0
RIR2.6
RIR3.6
RL1
RIR2.7
RIR3.7
RLB
CCR1.4
CCR7.6
Changes In Device Pin Out
Package Types
The DS2152L is offered in a 100 pin 14 x 14 x 1.4 mm LQFP. The DS2151Q is offered in a 44 pin 16.7 x
16.7 x 4.0 mm PLCC. Values listed are for body dimensions.
Device Pin Differences
Control Port Pins
DS2152L
DS2151Q
Description
INT
INT1, INT2
Flags host controller during conditions and change of conditions in the Status Registers 1 and 2, and the FDL Status Register.
TEST
N/A
Device pin tri-state enable.
MUX
N/A
Multiplexed/non-multiplexed bus operation select.
D0:D7 or AD0:AD7
AD0:AD7
Multiplexed/non multiplexed bus.
A0:A6
N/A
Address bus.
A7 OR ALE
ALE
A7 in non-multiplexed bus operation, ALE in multiplesed bus operation.
Line Interface Pins
DS2152L
DS2151Q
Description
MCLK
N/A
A 1.544 MHz TTL clock input used for clock/data recovery and for jitter attenuation.
MCLK, XTALD
XTAL1, XTAL2
1.544 MHz quartz crystal option instead of a TTL level clock at MCLK.
8XCLK
N/A
An 8 x 1.544 MHz clock that is frequency locked to either the clock/data recovery block or the TCLK1 pin.
LIUC
N/A
Line interface circuitry connect enable.
RPOSO
N/A
Receive line interface RPOS bipolar data output.
RNEGO
N/A
Receive line interface RNEG bipolar data output.
RCLKO
N/A
Buffered recovered clock from the T1 line.
TPOSI
N/A
Transmit line interface TPOS data input.
TNEGI
N/A
Transmit line interface TNEG data input.
TCLKI
N/A
Transmit line interface clock input.
Transmit Side Digital Pins
DS2152L
DS2151Q
Description
TSYSCLK
N/A
Transmit side elastic store clock.
TSSYNC
N/A
Transmit side elastic store frame or multiframe sync input.
TSIG
N/A
Outgoing signaling data input.
TESO
N/A
Transmit elastic store data output.
TDATA
N/A
Transmit formatter data input.
TPOSO
N/A
Transmit formatter TPOS data output.
TNEGO
N/A
A Transmit formatter TNEG data output.
TCLKO
N/A
Buffered clock used to move data through the transmit side formatter.