bt8970 Mindspeed Technologies, bt8970 Datasheet - Page 16

• Manufacturer Part Number: bt8970
• Description: Single-chip Hdsl Transceiver
• Manufacturer: Mindspeed Technologies

1.0 System Overview
1.2 Pin Descriptions
Table 1-2. Hardware Signal Definitions (2 of 4)
1-8
RQ[1]/
RDAT
RQ[0]/ BCLK
TQ[1]/ TDAT
TQ[0]
QCLK
TBCLK
RBCLK
Pin Label
Receive Quat 1/
Receive Data
Receive Quat 0/
Bit Clock
Transmit Quat 1/
Transmit Data
Transmit Quat 0
Quaternary Clock
Transmit
Baud-Rate Clock
Receive
Baud-Rate Clock
Signal Name
Preliminary Information/Conexant Proprietary and Confidential
I/O
O
O
O
I
I
I
I
RQ[1]/RDAT and RQ[0]/BCLK are bimodal outputs that represent the sign and
magnitude bits of the received quaternary output symbol in parallel channel unit
modes (RQ[1], RQ[0]), and the serial-data and bit-clock outputs in serial chan-
nel unit modes (RDAT, BCLK). Behavior of these outputs is configurable through
the Channel Unit Interface Modes Register [CU_interface_modes; 0x06] for par-
allel master, parallel slave, serial magnitude-bit-first and serial sign-bit-first
operations.
(master mode) or the rising/falling edge (programmable) of RBCLK (slave
mode).
TQ[1]/TDAT and TQ[0] are bimodal inputs that represent the sign and magni-
tude bits of the quaternary input symbol to be transmitted in parallel channel
unit modes (TQ[1], TQ[0]), and the serial data input in serial channel unit modes
(TDAT). Interpretation of these inputs is configurable through the Channel Unit
Interface Modes Register [CU_Interface_modes; 0x06] for parallel master, par-
allel slave, serial magnitude-bit-first and serial sign-bit-first operations.
(master mode) or the rising/falling edge (programmable) of TBCLK (slave
mode).
edge of BCLK.
Runs at the symbol rate. It defines the data on the TQ and RQ interfaces. QCLK
is also used to frame transmit/receive quats in serial mode.
Functions as the transmit baud-rate clock input. It must be frequency locked to
QCLK. This input is used only when the channel unit interface is in parallel slave
mode. If it is unused, it should be tied to VDD2 or DGND.
Functions as the receive baud-rate clock input. It must be frequency locked to
QCLK. This input is used only when the channel unit interface is in parallel slave
mode. If it is unused, it should be tied to VDD2 or DGND.
For parallel mode operation:
RQ[1] = Sign bit output
RQ[0] = Magnitude bit output
Both outputs are updated at the symbol rate on the rising edge of QCLK
For serial mode operation:
RDAT = Serial quaternary data output
BCLK = Bit-rate (two times symbol rate) clock output
RDAT is updated at the bit rate on the rising edge of BCLK
For parallel mode operation:
TQ[1] = Sign bit input
TQ[0] = Magnitude bit input
Both inputs are sampled at the symbol rate on the falling edge of QCLK
For serial mode operation:
TDAT = Serial quaternary data input
TQ0 = Don’t care (tie or pull up to supply rail)
TDAT is sampled at the bit rate (two times the symbol rate) on the falling
Channel Unit Interface
Conexant
Definition
Single-Chip HDSL Transceiver
100101B
Bt8970