Freescale Semiconductor, Inc.
Table 2-1. Signal Index (Continued)
Input/
Signal Name
Mnemonic
Function
Output
Clock Mode Select/
Port B0
MODCK
Selects the source of the internal system clock upon reset
or becomes a parallel I/O port
In/I/O
Instruction Fetch/
Development Serial In
IFETCH/DSI
IPIPE/DSO
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
Out/In
Instruction Pipe/
Development Serial Out
Used to track movement of words through the instruction
pipeline or provides background debug mode serial out
Out/Out
In/—
Breakpoint/Development
Serial Clock
BKPT/DSCLK Signals a hardware breakpoint to the CPU32 or provides
background debug mode serial clock
Freeze
FREEZE
Indicates that the CPU32 has entered background debug
mode
Out
Transmit Data
Clear-to-Send
TxDA, TxDB
Transmitter serial data output from the serial module
Out
In
CTSA, CTSB Serial module clear-to-send inputs
Request-to-Send/
OP1, OP0
RTSB, RTSA Channel request-to-send outputs or discrete outputs
Out/Out
Serial Crystal Oscillator
X1, X2
Connections for an external crystal to the serial module
internal oscillator circuit
Serial Clock
SCLK
External serial module clock input
In
Transmitter Ready/OP6
T≈RDYA
Indicates transmit buffer has a character or becomes a
parallel output
Out/Out
Receiver Ready/
FIFO Full/OP4
R≈RDYA
Indicates receive buffer has a character, the receiver
FIFO buffer is full or becomes a parallel output
Out/Out/Out
In
DMA Request
DRE
Input that starts a DMA process
Q2, DREQ1
DMA Acknowledge
DMA Done
DACK2,
DACK1
Output that signals an access during DMA
Bi-directional signal that indicates the last transfer
Counter enable input to timer
Out
I/O
In
DONE2,
DONE1
Timer Gate
TGATE2,
TGATE1
Timer Input
TIN2, TIN1
Time reference input to timer
Output waveform from timer
In
Timer Output
TOUT2,
TOUT1
Out
Test Clock
TCK
TMS
TDI
Provides a clock for IEEE 1149.1 test logic
Controls test mode operations
In
In
Test Mode Select
Test Data In
Shifts in instructions and test data
Shifts out instructions and test data
In
Test Data Out
Synchronizer Power
TDO
Out
—
V
Quiet power supply to VCO; also used to control
synthesizer mode after reset.
CCSYN
System Power Supply
and Ground
V
CC
, GND
Power supply and ground to the MC68340
—
MOTOROLA
MC68340 USER’S MANUAL
2- 3
For More Information On This Product,
Go to: www.freescale.com
FREESCALE [ Freescale ]
