Toshiba TLCS-870/C Series Manual page 66

5. I/O Ports
The TMP86PM29BUG has 6 parallel input/output ports (39 pins) as follows.
Port P1
Port P2
Port P3
Port P5
Port P6
Port P7
Each output port contains a latch, which holds the output data. All input ports do not have latches, so the external
input data should be externally held until the input data is read from outside or reading should be performed several
timer before processing. Figure 5-1 shows input/output timing examples.
External data is read from an I/O port in the S1 state of the read cycle during execution of the read instruction. This
timing cannot be recognized from outside, so that transient input such as chattering must be processed by the pro-
gram.
Output data changes in the S2 state of the write cycle during execution of the instruction which writes to an I/O
port.
nstruction
execution cycle
nput strobe
Data input
nstruction
execution cycle
Output strobe
Data output
Note: The positions of the read and write cycles may vary, depending on the instruction.
Primary Function
External interrupt input, serial interface input/output, UART input/output and
8-bit I/O port
segment output.
Low-frequency resonator connections, external interrupt input, STOP mode
3-bit I/O port
release signal input.
4-bit I/O port Timer/counter input/output and divider output.
8-bit I/O port Segment output.
Analog input, external interrupt input, timer/counter input and STOP mode
8-bit I/O port
release signal input.
8-bit I/O port Segment output.
Fetch cycle
S0 S1 S2 S3
Fetch cycle
S0 S1 S2 S3
Figure 5-1 Input/Output Timing (Example)
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Secondary Functions
Fetch cycle Read cycle
S0 S1 S2 S3 S0 S1 S2
Ex: LD A, (x)
(a) nput timing
Fetch cycle Write cycle
S0 S1 S2 S3 S0 S1 S2
Ex: LD (x), A
Old New
(b) Output timing
TMP86PM29BUG
S3
S3