Zilog Z80180 - Manual (Page 166)

Z8018x
Family MPU User Manual
UM005003-0703
151
Figure 58. CSI/O Interrupt Request Generation
CSI/O Operation
The CSI/O is operated using status polling or interrupt driven algorithms.
•
Transmit–Polling
a. Poll the TE bit in CNTR until TE =
0
.
b. Write the transmit data into TRDR.
c. Set the TE bit in CNTR to
1
.
d. Repeat steps 1 to 3 for each transmit data byte.
•
Transmit–Interrupts
a. Poll the TE bit in CNTR until TE =
0
.
b. Write the first transmit data byte into TRDR.
c. Set the TE and EIE bits in CNTR to
1
.
d. When the transmit interrupt occurs, write the next transmit data
byte into TRDR.
e. Set the TE bit in CNTR to
1
.
f. Repeat steps 4 and 5 for each transmit data byte.
•
Receive –Polling
a. Poll the RE bit in CNTR until RE =
0
.
b. Set the RE bit in CNTR to
1
.
EF
EIE
IEF1
CSI/O
Interrupt Request