10.1.3 Interfacing in SPI Mode

The SAMA7G54 SOM Series offers 11 FLEXCOM interfaces configured in SPI mode.

The SPI circuit is a synchronous serial data link that provides communication with external devices in Host or Client mode. It also enables communication between processors if an external processor is connected to the system.

The Serial Peripheral Interface is essentially a shift register that serially transmits data bits to other SPI devices. During a data transfer, one SPI system acts as the “host,” which controls the data flow, while the other devices act as “clients,” which have data shifted in and out by the host. Different CPUs can take turns being hosts (multiple host protocol, as opposed to single host protocol, where one CPU is always the host while all others are always clients). One host can simultaneously shift data into multiple clients. However, only one client can drive its output to write data back to the host at any given time.

A client device is selected when the host asserts its NSS signal. When multiple client devices are available, the host generates a separate client select signal (NPCS) for each.

The SPI system consists of two data lines and two control lines:

Host Out Client In (MOSI)—This data line supplies the output data from the host shifted into the input(s) of the client(s).
Host In Client Out (MISO)—This data line supplies the output data from a client to the input of the host. There may be no more than one client transmitting data during any particular transfer.
Serial Clock (SPCK)—This control line is driven by the host and regulates the flow of the data bits. The host can transmit data at a variety of baud rates; there is one SPCK pulse for each bit transmitted.
Client Select (NSS)—This control line allows clients to be turned on and off by hardware.

Table 10-24. FLEXCOM0 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM0	1	125	PA0	SPI Host Output Client Input (MOSI)
		130	PA1	SPI Host Input Client Output (MISO)
		126	PA2	SPI Serial Clock (SPCK)
		128	PA3	SPI Chip Select 0 (NPCS0)
		121	PA4	SPI Chip Select 1 (NPCS1)
FLEXCOM0	4	46	PE3	SPI Host Output Client Input (MOSI)
		49	PE4	SPI Host Input Client Output (MISO)
		48	PE5	SPI Serial Clock (SPCK)
		50	PE6	SPI Chip Select 0 (NPCS0)

Table 10-25. FLEXCOM1 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM1	1	127	PA5	SPI Host Output Client Input (MOSI)
		124	PA6	SPI Host Input Client Output (MISO)
		132	PA13	SPI Serial Clock (SPCK)
		131	PA12	SPI Chip Select 0 (NPCS0)
		133	PA14	SPI Chip Select 1 (NPCS1)
FLEXCOM1	2	20	PD12	SPI Host Output Client Input (MOSI)
		21	PD13	SPI Host Input Client Output (MISO)
		22	PD14	SPI Serial Clock (SPCK)
		19	PD15	SPI Chip Select 0 (NPCS0)
		24	PD16	SPI Chip Select 1 (NPCS1)
FLEXCOM1	3	126	PA2	SPI Host Output Client Input (MOSI)
		128	PA3	SPI Host Input Client Output (MISO)
		22	PD14	SPI Serial Clock (SPCK)
		19	PD15	SPI Chip Select 0 (NPCS0)
		24	PD16	SPI Chip Select 1 (NPCS1)
FLEXCOM1	4	87	PC9	SPI Host Output Client Input (MOSI)
		88	PC10	SPI Host Input Client Output (MISO)
		22	PD14	SPI Serial Clock (SPCK)
		19	PD15	SPI Chip Select 0 (NPCS0)
		24	PD16	SPI Chip Select 1 (NPCS1)

Table 10-26. FLEXCOM2 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM2	1	123	PA7	SPI Host Output Client Input (MOSI)
		122	PA8	SPI Host Input Client Output (MISO)
		119	PA9	SPI Serial Clock (SPCK)
		120	PA10	SPI Chip Select 0 (NPCS0)
		129	PA11	SPI Chip Select 1 (NPCS1)
FLEXCOM2	2	23	PD17	SPI Host Output Client Input (MOSI)
		111	PD18	SPI Host Input Client Output (MISO)
		110	PD19	SPI Serial Clock (SPCK)
		29	PD20	SPI Chip Select 0 (NPCS0)
		26	PD21	SPI Chip Select 1 (NPCS1)
FLEXCOM2	3	121	PA4	SPI Host Output Client Input (MOSI)
		127	PA5	SPI Host Input Client Output (MISO)
		110	PD19	SPI Serial Clock (SPCK)
		29	PD20	SPI Chip Select 0 (NPCS0)
		26	PD21	SPI Chip Select 1 (NPCS1)
FLEXCOM2	4	89	PC11	SPI Host Output Client Input (MOSI)
		90	PC12	SPI Host Input Client Output (MISO)
		110	PD19	SPI Serial Clock (SPCK)
		29	PD20	SPI Chip Select 0 (NPCS0)
		26	PD21	SPI Chip Select 1 (NPCS1)

Table 10-27. FLEXCOM3 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM3	1	180	PA15	SPI Host Output Client Input (MOSI)
		179	PA16	SPI Host Input Client Output (MISO)
		178	PA17	SPI Serial Clock (SPCK)
		177	PA18	SPI Chip Select 0 (NPCS0)
		182	PA19	SPI Chip Select 1 (NPCS1)
FLEXCOM3	2	55	PC0	SPI Host Output Client Input (MOSI)
		56	PC1	SPI Host Input Client Output (MISO)
		53	PB29	SPI Serial Clock (SPCK)
		58	PB30	SPI Chip Select 0 (NPCS0)
		54	PB31	SPI Chip Select 1 (NPCS1)
FLEXCOM3	3	124	PA6	SPI Host Output Client Input (MOSI)
		123	PA7	SPI Host Input Client Output (MISO)
		53	PB29	SPI Serial Clock (SPCK)
		58	PB30	SPI Chip Select 0 (NPCS0)
		54	PB31	SPI Chip Select 1 (NPCS1)
FLEXCOM3	4	91	PC13	SPI Host Output Client Input (MOSI)
		92	PC14	SPI Host Input Client Output (MISO)
		53	PB29	SPI Serial Clock (SPCK)
		58	PB30	SPI Chip Select 0 (NPCS0)
		54	PB31	SPI Chip Select 1 (NPCS1)
FLEXCOM3	5	24	PD16	SPI Host Output Client Input (MOSI)
		23	PD17	SPI Host Input Client Output (MISO)
		53	PB29	SPI Serial Clock (SPCK)
		58	PB30	SPI Chip Select 0 (NPCS0)
		54	PB31	SPI Chip Select 1 (NPCS1)

Table 10-28. FLEXCOM4 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM4	1	175	PA20	SPI Host Output Client Input (MOSI)
		178	PA21	SPI Host Input Client Output (MISO)
		176	PA22	SPI Serial Clock (SPCK)
		184	PA23	SPI Chip Select 0 (NPCS0)
		183	PA24	SPI Chip Select 1 (NPCS1)
FLEXCOM4	2	57	PC2	SPI Host Output Client Input (MOSI)
		59	PC3	SPI Host Input Client Output (MISO)
		60	PC4	SPI Serial Clock (SPCK)
		61	PC5	SPI Chip Select 0 (NPCS0)
		62	PC6	SPI Chip Select 1 (NPCS1)
FLEXCOM4	3	122	PA8	SPI Host Output Client Input (MOSI)
		119	PA9	SPI Host Input Client Output (MISO)
		60	PC4	SPI Serial Clock (SPCK)
		61	PC5	SPI Chip Select 0 (NPCS0)
		62	PC6	SPI Chip Select 1 (NPCS1)
FLEXCOM4	4	93	PC15	SPI Host Output Client Input (MOSI)
		99	PC16	SPI Host Input Client Output (MISO)
		60	PC4	SPI Serial Clock (SPCK)
		61	PC5	SPI Chip Select 0 (NPCS0)
		62	PC6	SPI Chip Select 1 (NPCS1)
FLEXCOM4	5	111	PD18	SPI Host Output Client Input (MOSI)
		110	PD19	SPI Host Input Client Output (MISO)
		60	PC4	SPI Serial Clock (SPCK)
		61	PC5	SPI Chip Select 0 (NPCS0)
		62	PC6	SPI Chip Select 1 (NPCS1)

Table 10-29. FLEXCOM5 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM5	1	187	PA28	SPI Host Output Client Input (MOSI)
		188	PA29	SPI Host Input Client Output (MISO)
		185	PA26	SPI Serial Clock (SPCK)
		186	PA27	SPI Chip Select 0 (NPCS0)
		181	PA25	SPI Chip Select 1 (NPCS1)
FLEXCOM5	2	30	PD25	SPI Host Output Client Input (MOSI)
		36	PD26	SPI Host Input Client Output (MISO)
		34	PD27	SPI Serial Clock (SPCK)
		35	PD28	SPI Chip Select 0 (NPCS0)
		33	PD29	SPI Chip Select 1 (NPCS1)
FLEXCOM5	3	120	PA10	SPI Host Output Client Input (MOSI)
		129	PA11	SPI Host Input Client Output (MISO)
		34	PD27	SPI Serial Clock (SPCK)
		35	PD28	SPI Chip Select 0 (NPCS0)
		33	PD29	SPI Chip Select 1 (NPCS1)
FLEXCOM5	4	100	PC17	SPI Host Output Client Input (MOSI)
		101	PC18	SPI Host Input Client Output (MISO)
		34	PD27	SPI Serial Clock (SPCK)
		35	PD28	SPI Chip Select 0 (NPCS0)
		33	PD29	SPI Chip Select 1 (NPCS1)
FLEXCOM5	5	29	PD20	SPI Host Output Client Input (MOSI)
		26	PD21	SPI Host Input Client Output (MISO)
		34	PD27	SPI Serial Clock (SPCK)
		35	PD28	SPI Chip Select 0 (NPCS0)
		33	PD29	SPI Chip Select 1 (NPCS1)

Table 10-30. FLEXCOM6 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM6	1	6	PB2	SPI Host Output Client Input (MOSI)
		5	PB1	SPI Host Input Client Output (MISO)
		4	PA31	SPI Serial Clock (SPCK)
		7	PB0	SPI Chip Select 0 (NPCS0)
		3	PA30	SPI Chip Select 1 (NPCS1)

Table 10-31. FLEXCOM7 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM7	2	85	PC7	SPI Host Output Client Input (MOSI)
		86	PC8	SPI Host Input Client Output (MISO)
		87	PC9	SPI Serial Clock (SPCK)
		88	PC10	SPI Chip Select 0 (NPCS0)
		89	PC11	SPI Chip Select 1 (NPCS1)
FLEXCOM7	3	181	PA25	SPI Host Output Client Input (MOSI)
		185	PA26	SPI Host Input Client Output (MISO)
		87	PC9	SPI Serial Clock (SPCK)
		88	PC10	SPI Chip Select 0 (NPCS0)
		89	PC11	SPI Chip Select 1 (NPCS1)
FLEXCOM7	4	52	PB28	SPI Host Output Client Input (MOSI)
		53	PB29	SPI Host Input Client Output (MISO)
		87	PC9	SPI Serial Clock (SPCK)
		88	PC10	SPI Chip Select 0 (NPCS0)
		89	PC11	SPI Chip Select 1 (NPCS1)

Table 10-32. FLEXCOM8 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM8	1	144	PB8	SPI Host Output Client Input (MOSI)
		156	PB9	SPI Host Input Client Output (MISO)
		148	PB10	SPI Serial Clock (SPCK)
		158	PB11	SPI Chip Select 0 (NPCS0)
		157	PB12	SPI Chip Select 1 (NPCS1)
FLEXCOM8	2	92	PC14	SPI Host Output Client Input (MOSI)
		91	PC13	SPI Host Input Client Output (MISO)
		90	PC12	SPI Serial Clock (SPCK)
		93	PC15	SPI Chip Select 0 (NPCS0)
		99	PC16	SPI Chip Select 1 (NPCS1)
FLEXCOM8	3	186	PA27	SPI Host Output Client Input (MOSI)
		187	PA28	SPI Host Input Client Output (MISO)
		90	PC12	SPI Serial Clock (SPCK)
		93	PC15	SPI Chip Select 0 (NPCS0)
		99	PC16	SPI Chip Select 1 (NPCS1)
FLEXCOM8	4	58	PB30	SPI Host Output Client Input (MOSI)
		54	PB31	SPI Host Input Client Output (MISO)
		90	PC12	SPI Serial Clock (SPCK)
		93	PC15	SPI Chip Select 0 (NPCS0)
		99	PC16	SPI Chip Select 1 (NPCS1)

Table 10-33. FLEXCOM9 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM9	1	151	PB13	SPI Host Output Client Input (MOSI)
		155	PB14	SPI Host Input Client Output (MISO)
		154	PB15	SPI Serial Clock (SPCK)
		152	PB16	SPI Chip Select 0 (NPCS0)
		159	PB17	SPI Chip Select 1 (NPCS1)

Table 10-34. FLEXCOM11 Interface Configurations in SPI Mode
Interface Instance	IO Set	Pin No.	Pin Name	Function
FLEXCOM11	1	139	PB3	SPI Host Output Client Input (MOSI)
		140	PB4	SPI Host Input Client Output (MISO)
		141	PB5	SPI Serial Clock (SPCK)
		142	PB6	SPI Chip Select 0 (NPCS0)
		143	PB7	SPI Chip Select 1 (NPCS1)
FLEXCOM11	3	5	PB1	SPI Host Output Client Input (MOSI)
		6	PB2	SPI Host Input Client Output (MISO)
		141	PB5	SPI Serial Clock (SPCK)
		142	PB6	SPI Chip Select 0 (NPCS0)
		143	PB7	SPI Chip Select 1 (NPCS1)
FLEXCOM11	4	60	PC4	SPI Host Output Client Input (MOSI)
		61	PC5	SPI Host Input Client Output (MISO)
		141	PB5	SPI Serial Clock (SPCK)
		142	PB6	SPI Chip Select 0 (NPCS0)
		143	PB7	SPI Chip Select 1 (NPCS1)