HD64570 HITACHI [Hitachi Semiconductor], HD64570 Datasheet - Page 348

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

Reception Processing Routine: Two examples of reception processing routines are given in
figures 9.3 and 9.4.
Rev. 0, 07/98, page 332 of 453
Load ACC contents
Issue EI instruction
(data) to B register
ACC data = ETX?
contents to ACC
data to memory
being received?
Transfer ACC
CRC code
Load TRB
Start
Return
Figure 9.3 RXRDY Interrupt Processing Routine (using HD64180)
No
No
Yes
Yes
ACC:
TRB:
CMD:
ST2:
EOM:
ETX:
ETB:
Next data is second
code byte being
CRC code byte
Second CRC
Next data is
CRC code
received?
Accumulator
TX/RX buffer register
Command register
Status register 2
End of message command
Control character (end of text)
Control character (end of block)
No
Yes
(CMD
(CMD
Wait for 15 system
Read ST2 contents
calculation forcing
reject command
Issue message
Issue RX CRC
clock cycles
to memory
command
00011000)
00010101)