HD64570 HITACHI [Hitachi Semiconductor], HD64570 Datasheet - Page 345

• Manufacturer Part Number: HD64570
• Description: Serial Communications Adaptor
• Manufacturer: HITACHI [Hitachi Semiconductor]

Issue EI instruction
Write ACC data to
Load memory data
TRB and transmit
ACC data = E
ETX or ETB?
Return
to ACC
Start
Figure 9.1 TXRDY Interrupt Processing Routine (using HD64180)
No
Yes
(CMD
ACC data = ETX?
Issue EOM
00000110)
No
ACC:
CMD:
TRB:
EOM:
ETX:
ETB:
Accumulator
Command register
TX/RX buffer register
End of message command
Control character (end of text)
Control character (end of block)
Yes
Rev. 0, 07/98, page 329 of 453
(CMD
(CMD
(ETX) to TRB and
Issue TX disable
Write ACC data
Issue EOM
command
transmit
00000110)
00000011)