CY8C20X34 CYPRESS [Cypress Semiconductor], CY8C20X34 Datasheet - Page 53

• Manufacturer Part Number: CY8C20X34
• Description: Technical Reference Manual (TRM)
• Manufacturer: CYPRESS [Cypress Semiconductor]

This chapter discusses the General Purpose IO (GPIO) and its associated registers, which is the circuit responsible for inter-
facing to the IO pins of a PSoC device. The GPIO blocks provide the interface between the M8C core and the outside world.
They offer a large number of configurations to support several types of input/output (IO) operations for both digital and analog
systems. For a complete table of the GPIO registers, refer to the
quick reference of all PSoC registers in address order, refer to the
6.1
The GPIO in the CY8C20x34 PSoC device is all uniform,
except the Port 1 GPIO has stronger high drive and an
option for regulated output level. These distinctions are dis-
cussed in more detail in the section
page
6.1.1
The GPIO contains input buffers, output drivers, and config-
uration logic for connecting the PSoC device to the outside
world.
PSoC CY8C20x34 TRM, Version 1.0
6.
54.
Drive Modes
DM1
Architectural Description
Write PRTxDR
0
0
1
1
Note Alt. Select/
Data is not available
on all pins.
General Purpose IO (GPIO)
General Description
Alt. Select
DM0
Alt. Data
0
1
0
1
Drive Mode
Resistive Pull Up
Strong Drive
High Impedance Analog
Open Drain Low
2:1
DM1
DM0
“Port 1 Distinctions” on
Logic
Drive
Diagram
Number Data = 0 Data = 1
REG_EN
0
1
3
2
Figure 6-1. GPIO Block Diagram
Vdd
Strong
Strong
Strong
Hi-Z
5.6k
LDO
Vdd
Resistive
Strong
Hi-Z
Hi-Z
Vdd
Port 1
Only
IO Ports are arranged with (up to) 8 bits per port. Each full
port contains eight identical GPIO blocks. Each GPIO block
can be used for the following types of IO:
Each IO pin also has several drive modes, as well as inter-
rupt capabilities. All GPIO pins provide both digital IO and
analog input capability.
“Summary Table of the Core Registers” on page
Register Reference chapter on page
Digital IO (digital input and output controlled by software)
Analog IO
0.
DM(1:0)=10b
1.
Read PRTxDR
2.
Pin
139.
interrupt logic)
(e.g., I2C)
Data
Alt. Input
Bus
(to GPIO
3.
INBUF
24. For a
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