Z8018x Family
MPU User Manual
151
IEF1
CSI/O
Interrupt Request
EF
EIE
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.
UM005001-ZMP0400
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