AT83C26-RKRUL Atmel, AT83C26-RKRUL Datasheet - Page 7

• Manufacturer Part Number: AT83C26-RKRUL
• Description: RFID Modules & Development Tools 3V Smart card reader
• Manufacturer: Atmel

Pad Type Description
Input/Output with Pull-up Configuration (IO1, IO2, AUX1, AUX2)
Figure 1. Input/Output with Pull-up Configuration
Input/Output with Pull-up Configuration (CIOn with n = 1, 2, 3, 4, 5) and (CC4n, CC8n with n = 1,
2)
Figure 2. Input/Output with Pull-up Configuration
7511D–SCR–02/07
Port latch
Data
Port latch
Data
To simplify the understanding of Figure 1. to Figure 8., a shortcut is possible by replacing the
weak transistor by a 100k Ohms pull-up resistor, the medium transistor by a
10k Ohms pull-up resistor and the strong transistor by a 1k Ohms pull-up resistor.
This output type can be used as both an input and output without the need to reconfigure the
port. This is possible because when the port outputs a logic high, it is weakly driven, allowing an
external device to pull the pin low. When the port outputs a logic low state, it is driven strongly
and able to sink a fairly large current.
2 DCCLK
CLOCK DELAY
2 DCCLK
CLOCK DELAY
Input
Data
Input
Data
NMOS
PMOS
NMOS
N
PMOS
P
Strong
N
P
Strong
P
Medium
P
Keep
Slew control
with
CIOn_SLEW_CTRL bits
(n= 1 to 5)
AT83C26
Pin
Pin
7