8.1.1 Interfacing in I²C Mode

Ten Flexible Serial Communication Controller (FLEXCOM) interfaces configurable in TWI mode, and one TWI interface, are available on the SAM9X60D1G-I/LZB.

FLEXCOM offers several serial communication protocols that are managed by the USART, SPI and TWI submodules.

The Two-Wire Interface (TWI) can interconnect with external components on a unique two-wire bus, made up of one clock line and one data line with speeds of up to 400 Kbits/s in Fast mode and up to 3.4 Mbits/s in High-Speed Client mode only, based on a byte-oriented transfer format.

It can be used with any Two-Wire Interface bus Serial EEPROM and I²C-compatible devices, such as a Real-Time Clock (RTC), a dot matrix/graphic LCD controller or a temperature sensor. The TWI is programmable as a host or a client with sequential or single-byte access. Multiple host capability is supported.

Table 8-1. I²C Interface Configurations
Interface Instance IO Set Pin No. PIO Pin Name Comment
FLEXCOM0 1 21 PA0 FLEXCOM0_IO0_TWD_PA0 No external pull-up needed. Already integrated in the SAM9X60D1G-I/LZB.
22 PA1 FLEXCOM0_IO1_TWCK_PA1
FLEXCOM1 1 73 PA5 FLEXCOM1_IO0 External pull-up needed in case the FLEXCOM interface is used as an I²C/TWI interface.
74 PA6 FLEXCOM1_IO1
FLEXCOM2 1 32 PA7 FLEXCOM2_IO0
33 PA8 FLEXCOM2_IO1
FLEXCOM3 1 120 PC22 FLEXCOM3_IO0
121 PC23 FLEXCOM3_IO1
FLEXCOM4 1 145 PA12 FLEXCOM4_IO0
144 PA11 FLEXCOM4_IO1
FLEXCOM5 1, 2 35 PA22 FLEXCOM5_IO0
36 PA21 FLEXCOM5_IO1
FLEXCOM6 1 80 PA30 FLEXCOM6_IO0
79 PA31 FLEXCOM6_IO1
FLEXCOM7 1 92 PC0 FLEXCOM7_IO0
93 PC1 FLEXCOM7_IO1
FLEXCOM9 1 102 PC8 FLEXCOM9_IO0
104 PC9 FLEXCOM9_IO1
FLEXCOM10 1 111 PC16 FLEXCOM10_IO0 External pull-up needed in case the FLEXCOM interface is used as an I²C/TWI interface.
112 PC17 FLEXCOM10_IO1
FLEXCOM11 1 64 PB19 FLEXCOM11_IO0
60 PB20 FLEXCOM11_IO1
FLEXCOM12 1 61 PB21 FLEXCOM12_IO0
62 PB22 FLEXCOM12_IO1