TMP86PM29BFG Datasheet, PDF (65/204 Pages) Toshiba Semiconductor – 8 Bit Microcontroller

TMP86PM29BFG
5. I/O Ports
The TMP86PM29BFG has 6 parallel input/output ports (39 pins) as follows.
Port P1
Port P2
Port P3
Port P5
Port P6
Port P7
Primary Function
8-bit I/O port
3-bit I/O port
4-bit I/O port
8-bit I/O port
8-bit I/O port
8-bit I/O port
Secondary Functions
External interrupt input, serial interface input/output, UART input/output and
segment output.
Low-frequency resonator connections, external interrupt input, STOP mode
release signal input.
Timer/counter input/output and divider output.
Segment output.
Analog input, external interrupt input, timer/counter input and STOP mode
release signal input.
Segment output.
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.
Instruction
execution cycle
Fetch cycle
Fetch cycle
Read cycle
S0 S1 S2 S3 S0 S1 S2 S3 S0 S1 S2 S3
Ex: LD A, (x)
Input strobe
Data input
Instruction
execution cycle
Output strobe
(a) Input timing
Fetch cycle
Fetch cycle
Write cycle
S0 S1 S2 S3 S0 S1 S2 S3 S0 S1 S2 S3
Ex: LD (x), A
Data output
Old
New
(b) Output timing
Note: The positions of the read and write cycles may vary, depending on the instruction.
Figure 5-1 Input/Output Timing (Example)
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