at43usb320a ATMEL Corporation, at43usb320a Datasheet - Page 67

• Manufacturer Part Number: at43usb320a
• Description: Full-speed Usb Microcontroller With An Embedded Hub
• Manufacturer: ATMEL Corporation

Port C
Port C as General
Digital I/O
1443E–USB–4/04
Port C is an 8-bit bi-directional I/O port with push-pull outputs. The Port C output buffers can
sink 4 mA
Three I/O memory address locations are allocated for the Port C, one each for the Data Regis-
ter
–
Data Direction Register are read/write.
Port C Data Register
Port C Data Direction Register
Port C Input Pins Address
The Port C Input Pins address PINC is not a register, and this address enables access to the
physical value on each Port C pin. When reading PORTC, the Port C Data Latch is read, and
when reading PINC, the logical values present on the pins are read.
All 8 pins in Port C have equal functionality when used as digital I/O pins.
PCn, General I/O pin: The DDCn bit in the DDRC register selects the direction of this pin, if
DDCn is set (one), PCn is configured as an output pin. If DDCn is cleared (zero), PCn is con-
figured as an input pin. The value of PORTCn has no meaning in this mode. The Port C pins
are tri-stated when a reset condition becomes active, even if the clock is not active.
Table 26. DDCn Effects on Port C Pins
Note:
DDCn
0
0
1
1
PINC, $13($33). The Port C Input Pins address is read only, while the Data Register and the
Read/Write
Initial value
Read/Write
Initial value
Read/Write
Initial value
$15 ($35)
$13 ($33)
$14 ($34)
–
Bit
Bit
Bit
PORTC, $15($35), Data Direction Register
n: 7…0, pin number
PORTC7
PINC7
DDC7
R/W
R/W
N/A
R
7
0
7
7
0
PORTCn
0
1
0
1
PORTC6
PINC6
DDC6
R/W
R/W
N/A
–
R
6
6
0
6
0
PORTC
–
PORTC5
PINC
PINC5
DDC5
R/W
R/W
N/A
R
5
0
5
0
5
–
DDRC
PORTC4
PINC4
DDC4
Input
Input
Output
Output
I/O
R/W
R/W
N/A
4
0
4
0
R
4
PORTC3
DDC3
PINC3
R/W
R/W
–
N/A
3
0
3
0
3
R
DDRC, $14($34) and the Port C Input Pins
PORTC2
PINC2
DDC2
R/W
R/W
N/A
R
2
0
2
0
2
Comment
Tri-state (Hi-Z)
Tri-state (Hi-Z)
Push-pull Zero Output
Push-pull One Output
PORTC1
AT43USB320A
PINC1
DDC1
R/W
R/W
N/A
R
1
0
1
0
1
PORTC0
PINC0
DDC0
R/W
R/W
N/A
R
0
0
0
0
0
PORTC
DDRC
PINC
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