Appendixes

Interfaces

XON/XOFF Protocol

Requirements to output X-ON code

•Communication is possible when the power is on.

•When the receive buffer has less than 128 bytes available, XOFF code is output, then the receive buffer has at least at least 1024 bytes available.

Requirements to output the X-OFF code

• When the receive buffer has less than 128 bytes available

Receive buffer

16K bytes

XOFF

128 bytes

1024 bytes

XON

DTR Protocol

Conditions when the DTR signal is “Ready (High)”

All the following conditions are satisfied.

• The receive buffer is 128 bytes or more available capacity.

*When the receive buffer has less than 128 bytes available and the DTR signal has changed to BUSY (Low) status, BUSY status is maintained until the capacity of the receive buffer has reached 1024 bytes or more.

Conditions when DTR signal is “Busy (Low)”

• When the receive buffer has fallen to less than 128 bytes available.

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