Motorola MC68340 ユーザーズマニュアル

MOTOROLA

2- 3

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

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

IPIPE/

DSO

Used to track movement of words through the instruction
pipeline or provides background debug mode serial out

Out/Out

Breakpoint/Development
Serial Clock

BKPT

/DSCLK

Signals a hardware breakpoint to the CPU32 or provides
background debug mode serial clock

In/—

Freeze

FREEZE

Indicates that the CPU32 has entered background debug
mode

Out

Transmit Data

TxDA, TxDB

Transmitter serial data output from the serial module

Out

Clear-to-Send

CTSA, CTSB

Serial module clear-to-send inputs

In

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

DMA Request

DRE

Q2, DREQ1

Input that starts a DMA process

In

DMA Acknowledge

DACK2,

DACK1

Output that signals an access during DMA

Out

DMA Done

DONE2,

DONE1

Bi-directional signal that indicates the last transfer

I/O

Timer Gate

TGATE2,

TGATE1

Counter enable input to timer

In

Timer Input

TIN2, TIN1

Time reference input to timer

In

Timer Output

TOUT2,

TOUT1

Output waveform from timer

Out

Test Clock

TCK

Provides a clock for IEEE 1149.1 test logic

In

Test Mode Select

TMS

Controls test mode operations

In

Test Data In

TDI

Shifts in instructions and test data

In

Test Data Out

TDO

Shifts out instructions and test data

Out

Synchronizer Power

VCCSYN

Quiet power supply to VCO; also used to control
synthesizer mode after reset.

—

System Power Supply
and Ground

VCC, GND

Power supply and ground to the MC68340

—

F

re

e

sc

a

le

 S

e

m

ic

o

n

d

u

c

to

r,

 I

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

 

Freescale Semiconductor, Inc.

For More Information On This Product,

   Go to: www.freescale.com

n

c

.

..