2 as311 functions, As311 overview – Toshiba AS311 User Manual

Page 11

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User’s

Manual

9

1. AS311 Overview


1.2 AS311 functions


From the point of view of T3, the AS311 works as communications driver. The

followings are the simplified explanations for T3 and AS311 functions.


When a message (one set of transmission characters) is received by AS311, the flag

which indicates the receiving complete will come ON. T3 can check the flag status then

read the message from the AS311 by using the READ instruction.


In case of transmitting a message (one set of transmission characters) from T3 through

AS311, T3 writes the message into the AS311 by using the WRITE instruction, then

sets the flag which instruct the AS311 to start transmitting the message.



T3

AS311


Register

Buffer memory


READ

Receiving

area

Receiving

Channel 1

WRITE

Transmitting

buffer

area

READ

Receiving

Transmitting

area

buffer

WRITE

Transmitting

area

Receiving

Channel 2

buffer


Transmitting

buffer




Here, a message (one set of transmission characters) means a string of ASCII

characters which is ended by specified trailing code. The default setting of the trailing

code is CR (carriage return code = H0D).


Applicable message format (default trailing code):

1

2

3

4

N-1 N

CR


N: message length = 896 bytes max.

In other words, the AS311 cannot be used for the data communication in which the

transmission message is ended by two or more types of trailing code.

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