Product Descriptions

1.4.2 Mac Serial Interface
￿ Standard

RS-423 compliant

￿ Synchronization

Synchronous

￿ Bit rate

Approximately 900 Kbps, 1.8 Mbps

￿ Word format

Start bit

1 bit

 

Data bit

8 bit

 

Parity bit

No parity bit

 

Stop bit1 bit

￿ Handshaking

X-ON/XOFF, DTR protocol

￿Adaptable connector 8-pin mini circular connector

￿Recommended I/F cable Apple System Peripheral-8 cable

Table 1-24. Connector Pin Assignment for Serial Interface

 

Pin No.

 

Signal Name

I/O

Function Description

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

SCLK

O

Synchronous clock

 

 

 

2

 

 

CTS

I

Clear to send

 

 

 

3

 

TxD-

O

Transmit data -

 

 

 

4

 

 

S.G.

I

Signal Ground

 

 

 

5

 

RxD-

I

Receive data -

 

 

 

6

 

TxD+

O

Balanced Transmit +

 

 

 

7

 

 

DTR

O

Data terminal ready

 

 

 

8

 

RxD+

I

Balanced Receive +

 

 

 

 

 

 

Table 1-25. X-ON/X-OFF, DTR Protocol

 

 

 

 

 

 

 

 

 

 

 

State

 

Buffer space

 

X-ON/X-OFF

DTR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Busy

 

Less than 1024 bytes

 

Send X-OFF code

Off

 

 

Ready

 

More than 2048 bytes

 

Send X-ON code

On

 

8 7 6

5

4

3

2 1

Figure 1-9.Serial Interface Connector Pin Assignment

1-20

Rev. A