Cypress FM4 Series - Configuration, Block Diagram, and Operation

CHAPTER 12: I/O Port
FM4 Peripheral Manual, Doc. No. 002-04856 Rev. *E 583
2. Configuration, Block Diagram, and Operation
This section explains the configuration, block diagram, and operation of the I/O port.
Configuration of the I/O Port
By setting registers of the I/O port, select Input/Output direction and select GPIO/peripheral.
Figure 2-1 shows the details of the I/O port.
Figure 2-1 Block Diagram of the I/O Port
Peripheral output signal 2
Input direction if there is
no output pin setting
Pin
DDR
PFR*
EPFR
Peripheral output signal 1
External bus output signal
Peripheral direction signal 2
Peripheral direction signal 1
External bus direction signal
PFR*
EPFR
*1
1
0
1
0
0
1
PDOR
EPFR
PDIR
PDIR (GPIO read) can be always read when digital input is selected
Special pin
ADC
USB
Oscillation
LCDC
*2
Special pin
judgement
Analog input is valid
when ADE/SPSR=1.
ADE/
SPSR/
DAE/
Peripheral
macro
Relocation
pin input
PCR*
PZR*
Hi-Z output
determination
Hi-Z output
determination
ADE/SPSR/DAE/
Deep standby transition reset
Deep standby transition reset
Special pin
DAC
output
Analog output is
valid when DAE=1
PDSR*
*1: When one of the followings is set, I/O port is set to input direction.
− ADE/SPSR=1
− DAE=1