SAM7S256_14 Datasheet, PDF (320/775 Pages) ATMEL Corporation – ARM-based Flash MCU

30.3 Block Diagram
Figure 30-1. Block Diagram
APB Bridge
PMC
MCK
Two-wire
Interface
PIO
TWI
Interrupt
AIC
TWCK
TWD
30.4 Application Block Diagram
Figure 30-2. Application Block Diagram
Host with
TWI
Interface
TWD
TWCK
Atmel TWI
Serial EEPROM
Slave 1
I²C RTC
Slave 2
Rp: Pull up value as given by the I²C Standard
30.4.1 I/O Lines Description
Table 30-3.
Pin Name
TWD
TWCK
I/O Lines Description
Pin Description
Two-wire Serial Data
Two-wire Serial Clock
VDD
Rp
Rp
I²C LCD
Controller
Slave 3
I²C Temp.
Sensor
Slave 4
Type
Input/Output
Input/Output
30.5 Product Dependencies
30.5.1 I/O Lines
Both TWD and TWCK are bidirectional lines, connected to a positive supply voltage via a current source or pull-up
resistor (see Figure 30-2 on page 320). When the bus is free, both lines are high. The output stages of devices
connected to the bus must have an open-drain or open-collector to perform the wired-AND function.
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
320