Motorola MC68340 User Manual page 37

Signal Name
Clock Mode Select/
Port B0
Instruction Fetch/
Development Serial In
Instruction Pipe/
Development Serial Out
Breakpoint/Development
Serial Clock
Freeze
Transmit Data
Clear-to-Send
Request-to-Send/
OP1, OP0
Serial Crystal Oscillator
Serial Clock
Transmitter Ready/OP6
Receiver Ready/
FIFO Full/OP4
DMA Request
DMA Acknowledge
DMA Done
Timer Gate
Timer Input
Timer Output
Test Clock
Test Mode Select
Test Data In
Test Data Out
Synchronizer Power
System Power Supply
and Ground
MOTOROLA
Freescale Semiconductor, Inc.
Table 2-1. Signal Index (Continued)
Mnemonic
MODCK Selects the source of the internal system clock upon reset
or becomes a parallel I/O port
IFETCH /DSI Indicates when the CPU32 is performing an instruction
word prefetch and when the instruction pipeline has been
flushed or provides background debug mode serial in
IPIPE/ DSO
Used to track movement of words through the instruction
pipeline or provides background debug mode serial out
BKPT /DSCLK Signals a hardware breakpoint to the CPU32 or provides
background debug mode serial clock
FREEZE Indicates that the CPU32 has entered background debug
mode
TxDA, TxDB Transmitter serial data output from the serial module
CTSA, CTSB
Serial module clear-to-send inputs
RTSB, RTSA Channel request-to-send outputs or discrete outputs
X1, X2 Connections for an external crystal to the serial module
internal oscillator circuit
SCLK External serial module clock input
T RDYA
Indicates transmit buffer has a character or becomes a
parallel output
R RDYA Indicates receive buffer has a character, the receiver
FIFO buffer is full or becomes a parallel output
DRE Input that starts a DMA process
Q2, DREQ1
DACK2,
Output that signals an access during DMA
DACK1
DONE2,
Bi-directional signal that indicates the last transfer
DONE1
TGATE2, Counter enable input to timer
TGATE1
TIN2, TIN1 Time reference input to timer
TOUT2, Output waveform from timer
TOUT1
TCK Provides a clock for IEEE 1149.1 test logic
TMS Controls test mode operations
TDI Shifts in instructions and test data
TDO Shifts out instructions and test data
V CCSYN Quiet power supply to VCO; also used to control
synthesizer mode after reset.
V CC , GND Power supply and ground to the MC68340
MC68340 USER'S MANUAL
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Function
Input/
Output
In/I/O
Out/In
Out/Out
In/—
Out
Out
In
Out/Out
In
Out/Out
Out/Out/Out
In
Out
I/O
In
In
Out
In
In
In
Out
—
—
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