ST72P264G2M6/XXX View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST72P264G2M6/XXX

8-BIT MCU WITH FLASH OR ROM MEMORY, ADC, TWO 16-BIT TIMERS, I2C, SPI, SCI INTERFACES

STMicroelectronics 

ST72260G, ST72262G, ST72264G

SERIAL PERIPHERAL INTERFACE (Cont’d)

11.4.8 Register Description

CONTROL REGISTER (SPICR)

Read/Write

Reset Value: 0000 xxxx (0xh)

7

0

SPIE SPE SPR2 MSTR CPOL CPHA SPR1 SPR0

Bit 7 = SPIE Serial Peripheral Interrupt Enable.

This bit is set and cleared by software.

0: Interrupt is inhibited

1: An SPI interrupt is generated whenever an End

of Transfer event, Master Mode Fault or Over-

run error occurs (SPIF=1, MODF=1 or OVR=1

in the SPICSR register)

Bit 6 = SPE Serial Peripheral Output Enable.

This bit is set and cleared by software. It is also

cleared by hardware when, in master mode, SS=0

(see Section 11.4.5.1 "Master Mode Fault

(MODF)" on page 79). The SPE bit is cleared by

reset, so the SPI peripheral is not initially connect-

ed to the external pins.

0: I/O pins free for general purpose I/O

1: SPI I/O pin alternate functions enabled

Bit 5 = SPR2 Divider Enable.

This bit is set and cleared by software and is

cleared by reset. It is used with the SPR[1:0] bits to

set the baud rate. Refer to Table 16 SPI Master

mode SCK Frequency.

0: Divider by 2 enabled

1: Divider by 2 disabled

Note: This bit has no effect in slave mode.

Bit 4 = MSTR Master Mode.

This bit is set and cleared by software. It is also

cleared by hardware when, in master mode, SS=0

(see Section 11.4.5.1 "Master Mode Fault

(MODF)" on page 79).

0: Slave mode

1: Master mode. The function of the SCK pin

changes from an input to an output and the func-

tions of the MISO and MOSI pins are reversed.

Bit 3 = CPOL Clock Polarity.

This bit is set and cleared by software. This bit de-

termines the idle state of the serial Clock. The

CPOL bit affects both the master and slave

modes.

0: SCK pin has a low level idle state

1: SCK pin has a high level idle state

Note: If CPOL is changed at the communication

byte boundaries, the SPI must be disabled by re-

setting the SPE bit.

Bit 2 = CPHA Clock Phase.

This bit is set and cleared by software.

0: The first clock transition is the first data capture

edge.

1: The second clock transition is the first capture

edge.

Note: The slave must have the same CPOL and

CPHA settings as the master.

Bits 1:0 = SPR[1:0] Serial Clock Frequency.

These bits are set and cleared by software. Used

with the SPR2 bit, they select the baud rate of the

SPI serial clock SCK output by the SPI in master

mode.

Note: These 2 bits have no effect in slave mode.

Table 16. SPI Master mode SCK Frequency

Serial Clock

fCPU/4

fCPU/8

fCPU/16

fCPU/32

fCPU/64

fCPU/128

SPR2

1

0

0

1

0

0

SPR1

0

0

0

1

1

1

SPR0

0

0

1

0

0

1

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