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CHAPTER 9 I/O PORT
9.7.2
Operations of Port 9
This section describes the operations of port 9.
■
Operations of Port 9
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Operation as an output port
•
Setting the corresponding DDR bit to "1" sets a pin as an output port.
•
For a peripheral function sharing pins, disable its output.
•
When a pin is set as an output port, it outputs the value of the PDR to pins.
•
If data is written to the PDR, the value is stored in the output latch and output to the pin as it is.
•
Reading the PDR returns the PDR value.
●
Operation as an input port
•
When setting the corresponding bit of DDR register to "0", it becomes input port.
•
Prohibit output in pins jointly used by a peripheral function.
•
When using a pin jointly used for LCD as an input port, set the V1 to V3 selection bits (VE2/VE1) ofthe
LCDC enable register (LCDCE1) to "0".
•
When data is written to the PDR register, the value is stored in the output latch, but not output to the pin.
•
The pin value can be read out by reading out the PDR register. Note, however, that for read-modify-
write commands, the value of the PDR register is read.
●
Operation as a peripheral function output
•
Setting the output enable bit of a peripheral function sets the corresponding pin as a peripheral function
output.
•
The pin value can be read from the PDR register even if the peripheral function output is enabled.
Therefore, the output value of a peripheral function can be read by the read operation on PDR register.
However, the read-modify-write command returns the PDR value.
●
Operation at reset
•
For P92 to P90, resetting the CPU initializes the DDR values to "0" and the VE2/VE1 bits in LCDCE1
to "1", and port input disabled.
•
For P95 and P94, resetting the CPU initializes the DDR values to "0", and sets the port input enabled.
●
Operation in stop mode and watch mode
•
If the pin state specification bit in the standby control register (STBC:SPL) is set to "1" when the device
switches to stop or watch mode, the pin is set forcibly to the high-impedance state regardless of the
DDR value. Note that the input is locked to "L" and blocked in order to prevent leaks due to freed input.
•
If the pin state specification bit is "0", the state remains in port I/O or peripheral function I/O and the
output is maintained.
●
Operation of the pull-up register
•
Writing "1" to the PUL internally connects the pull-up register to the pin. When the output is "L" level,
the pull-up register is disconnected regardless of the PUL value.
Summary of Contents for F2 MC-8FX Family
Page 2: ......
Page 4: ......
Page 34: ...20 CHAPTER 1 DESCRIPTION ...
Page 38: ...24 CHAPTER 2 HANDLING DEVICES ...
Page 39: ...25 CHAPTER 3 MEMORY SPACE This chapter describes memory space 3 1 Memory Space 3 2 Memory Map ...
Page 56: ...42 CHAPTER 5 CPU ...
Page 73: ...59 CHAPTER 6 CLOCK CONTROLLER ...
Page 96: ...82 CHAPTER 6 CLOCK CONTROLLER ...
Page 104: ...90 CHAPTER 7 RESET ...
Page 105: ...91 CHAPTER 8 INTERRUPTS This chapter explains the interrupts 8 1 Interrupts ...
Page 174: ...160 CHAPTER 10 TIMEBASE TIMER ...
Page 184: ...170 CHAPTER 10 TIMEBASE TIMER ...
Page 218: ...204 CHAPTER 13 WATCH PRESCALER ...
Page 257: ...243 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 261: ...247 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 288: ...274 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 301: ...287 CHAPTER 17 16 BIT PPG TIMER ...
Page 316: ...302 CHAPTER 17 16 BIT PPG TIMER ...
Page 382: ...368 CHAPTER 21 UART SIO DEDICATED BAUD RATE GENERATOR ...
Page 390: ...376 CHAPTER 22 I2C ...
Page 395: ...381 CHAPTER 22 I2C ...
Page 399: ...385 CHAPTER 22 I2C ...
Page 430: ...416 CHAPTER 23 10 BIT A D CONVERTER ...
Page 476: ...462 CHAPTER 24 LCD CONTROLLER ...
Page 482: ...468 CHAPTER 25 LOW VOLTAGE DETECTION RESET CIRCUIT ...
Page 494: ...480 CHAPTER 26 CLOCK SUPERVISOR ...
Page 507: ...493 CHAPTER 27 REAL TIME CLOCK ...
Page 523: ...509 CHAPTER 27 REAL TIME CLOCK ...
Page 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Page 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 554: ...540 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 564: ...550 CHAPTER 29 EXAMPLE OF SERIAL PROGRAMMING CONNECTION ...
Page 595: ...581 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 596: ...582 INDEX Index ...
Page 597: ...583 INDEX ...
Page 600: ...586 Pin Function Index ...
Page 602: ......