11.1.1 Interfacing in I²C/TWI Mode

Ten Flexible Serial Communication Controller (FLEXCOM) interfaces configurable in Two-Wire Interface (TWI) are available on the SAMA7D65 SOM Series.

The TWI can interconnect with external components on a unique two-wire bus, made up of one clock line and one data line.

The TWI supports the following modes/speeds:

Standard mode speed (100 kHz): Host, Multi-Host, Client
Fast mode speed (400 kHz): Host, Multi-Host, Client
Fast mode plus speed (1 MHz): Host, Multi-Host, Client
High-speed mode (1.7 MHz/3.4 MHz): Host, Client

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 11-1. I²C/TWI Interface Configurations
Interface Instance	IO Set	Pin No.	PIO	Pin Name	Comment
FLEXCOM0	2	179	PC7	FLEXCOM0_IO0	⁽¹⁾
FLEXCOM0	2	182	PC6	FLEXCOM0_IO1	⁽¹⁾
FLEXCOM1	1	123	PD7	FLEXCOM1_IO0	⁽¹⁾
FLEXCOM1	1	122	PD6	FLEXCOM1_IO1	⁽¹⁾
FLEXCOM1	2	210	PC14	FLEXCOM1_IO0	⁽¹⁾
FLEXCOM1	2	208	PC15	FLEXCOM1_IO1	⁽¹⁾
FLEXCOM1	3	191	PB28	FLEXCOM1_IO0	⁽¹⁾
FLEXCOM1	3	194	PB29	FLEXCOM1_IO1	⁽¹⁾
FLEXCOM2	1	15	PE8	FLEXCOM2_IO0	⁽¹⁾
FLEXCOM2	1	16	PE9	FLEXCOM2_IO1	⁽¹⁾
FLEXCOM2	4	45	PB15	FLEXCOM2_IO0	⁽¹⁾
FLEXCOM2	4	44	PB14	FLEXCOM2_IO1	⁽¹⁾
FLEXCOM3	2	38	PA24	FLEXCOM3_IO0	⁽¹⁾
FLEXCOM3	2	39	PA23	FLEXCOM3_IO1	⁽¹⁾
FLEXCOM3	3	126	PD1	FLEXCOM3_IO0	⁽¹⁾
FLEXCOM3	3	127	PD2	FLEXCOM3_IO1	⁽¹⁾
FLEXCOM3	4	7	PA14	FLEXCOM3_IO0	⁽¹⁾
FLEXCOM3	4	5	PA15	FLEXCOM3_IO1	⁽¹⁾
FLEXCOM4	1	3	PA18	FLEXCOM4_IO0	⁽¹⁾
FLEXCOM4	1	6	PA17	FLEXCOM4_IO1	⁽¹⁾
FLEXCOM5	1	80	PD16	FLEXCOM5_IO0	⁽¹⁾
FLEXCOM5	1	79	PD17	FLEXCOM5_IO1	⁽¹⁾
FLEXCOM5	2	61	PE3	FLEXCOM5_IO0	⁽¹⁾
FLEXCOM5	2	59	PE2	FLEXCOM5_IO1	⁽¹⁾
FLEXCOM6	2	141	PB24	FLEXCOM6_IO0	⁽¹⁾
FLEXCOM6	2	143	PB25	FLEXCOM6_IO1	⁽¹⁾
FLEXCOM6	3	69	PD24	FLEXCOM6_IO0	⁽¹⁾
FLEXCOM6	3	57	PD25	FLEXCOM6_IO1	⁽¹⁾
FLEXCOM6	4	73	PD18	FLEXCOM6_IO0	⁽¹⁾
FLEXCOM6	4	74	PD19	FLEXCOM6_IO1	⁽¹⁾
FLEXCOM7	1	85	PD8	FLEXCOM7_IO0	⁽¹⁾
FLEXCOM7	1	88	PD9	FLEXCOM7_IO1	⁽¹⁾
FLEXCOM7	2	58	PD27	FLEXCOM7_IO0	⁽¹⁾
FLEXCOM7	2	67	PD28	FLEXCOM7_IO1	⁽¹⁾
FLEXCOM7	3	124	PD5	FLEXCOM7_IO0	⁽¹⁾
FLEXCOM7	3	121	PD4	FLEXCOM7_IO1	⁽¹⁾
FLEXCOM8	2	95	PC27	FLEXCOM8_IO0	⁽¹⁾
FLEXCOM8	2	96	PC28	FLEXCOM8_IO1	⁽¹⁾
FLEXCOM8	3	142	PB26	FLEXCOM8_IO0	⁽¹⁾
FLEXCOM8	3	145	PB27	FLEXCOM8_IO1	⁽¹⁾
FLEXCOM9	1	204	PC8	FLEXCOM9_IO0	⁽¹⁾
FLEXCOM9	1	202	PC9	FLEXCOM9_IO1	⁽¹⁾
FLEXCOM9	2	180	PC3	FLEXCOM9_IO0	⁽¹⁾
FLEXCOM9	2	178	PC4	FLEXCOM9_IO1	⁽¹⁾

Note:

External pull-up needed in case the FLEXCOM interface is used as an I²C/TWI interface.