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1 control register (spcr) – Renesas SH7781 User Manual

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23. Serial Peripheral Interface (HSPI)

Rev.1.00 Jan. 10, 2008 Page 1155 of 1658

REJ09B0261-0100

23.3.1

Control Register (SPCR)

SPCR is a 32-bit readable/writable register that controls the transfer data of shift timing and
specifies the clock polarity and frequency.

16

17

18

19

20

21

22

23

24

25

26

27

28

29

31

30

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R

Bit:

Initial value:

R/W:

0

1

2

3

4

5

6

7

8

9

10

11

12

13

15

14

0

0

0

0

0

0

0

0

CLKC0

CLKC1

CLKC2

CLKC3

CLKC4

IDIV

CLKP

FBS

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R

R

R

R

R

R

R

R

Bit:

Initial value:

R/W:

Bit Bit

Name

Initial
Value R/W

Description

31 to 8

⎯ All

0

R

Reserved

These bits are always read as an undefined value. The
write value should always be 0.

7

FBS

0

R/W

First Bit Start

Controls the timing relationship between each bit of
transferred data and the serial clock.

0: The first bit transmitted from the HSPI module is set
up such that it can be sampled by the receiving device at
the first edge of HSPI_CLK specified by the register after
the HSPI_CS pin goes low. Similarly the first received bit
is sampled at the first edge of HSPI_CLK after the
HSPI_CS pin goes low.

1: The first bit transmitted from the HSPI module is set
up such that it can be sampled by the receiving device at
the second edge of HSPI_CLK after the HSPI_CS pin
goes low. Similarly the first received bit is sampled at the
second edge of HSPI_CLK specified by the register after
the HSPI_CS pin goes low.

6

CLKP

0

R/W

Serial Clock Polarity

0: HSPI_CLK signal is not inverted and so is low when
inactive.

1: HSPI_CLK signal is inverted and so is high when
inactive.