MC68HC708AS48 FREESCALE [Freescale Semiconductor, Inc], MC68HC708AS48 Datasheet - Page 353

• Manufacturer Part Number: MC68HC708AS48
• Description: Advance Information
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

20.6.1 Protocol Architecture
20.6.2 Rx and Tx Shift Registers
MC68HC708AS48
MOTOROLA
—
Rev. 4.0
The protocol handler contains the state machine, Rx shadow register, Tx
shadow register, Rx shift register, Tx shift register, and loopback
multiplexer as shown in
The Rx shift register gathers received serial data bits from the J1850 bus
and makes them available in parallel form to the Rx shadow register.
The Tx shift register takes data, in parallel form, from the Tx shadow
register and presents it serially to the state machine so that it can be
transmitted onto the J1850 bus.
DLOOP FROM BCR2
LOOPBACK CONTROL
Byte Data Link Controller–Digital (BDLC–D)
Figure 20-14. BDLC Protocol Handler Outline
Rx SHADOW REGISTER
Rx SHIFT REGISTER
Figure
BDRxD
MULTIPLEXER
LOOPBACK
TO CPU INTERFACE AND Rx/Tx BUFFERS
8
20-14.
TO PHYSICAL INTERFACE
Byte Data Link Controller–Digital (BDLC–D)
STATE MACHINE
BDTxD
Tx SHADOW REGISTER
Tx SHIFT REGISTER
BDLC Protocol Handler
Advance Information
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