Fujitsu FR81S 사용자 설명서
CHAPTER 11: I/O PORTS
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : I/O PORTS
FUJITSU SEMICONDUCTOR CONFIDENTIAL
53
5.1.4. External Bus Assignment
The external bus assignment is shown below.
Preparation
⋅
Since the pin will once function as a port as the result of step (1), set the DDR and PDR values in
advance if necessary.
⋅
For a pin with the AD converter function, set the applicable bit in the analog input enable register
(ADER) of the AD converter to "Port I/O mode". For information on the setting method, see
"CHAPTER: A/D CONVERTER".
(1)Set the PFR for the applicable pin to enable the port function.
(2)Disable the EPFRs for all other peripherals that use the same pin as the external bus.
(3)Set the PFR for the peripheral.
Figure 5-5 External Bus Assignment Procedure
Pin
EPFR
PFR
PDR
DDR
PDDR
EPFR
Peripheral
output value
External bus
Output value
Peripheral I/O
direction control
External bus I/O
direction control
To peripheral
input value
Input I/O relocation selection circuit
To input I/O relocation selection circuit
To external bus input value
Input value from each pins
To peripheral input value
(1)
(2)
(3)
MB91520 Series
MN705-00010-1v0-E
448