Table 64: spi command sequences, Figure 27 – Rainbow Electronics 71M6542G User Manual

Page 75

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75

A15

A14

A1

A0

C0

0

31

x

D6

D1

D0

D7

D6

D1

D0

C5

C6

C7

(From Host) SPI_CSZ

(From Host) SPI_CK

(From Host) SPI_DI

(From 654x) SPI_DO

8 bit CMD

16 bit Address

DATA[ADDR]

DATA[ADDR+1]

15

16

23

24

32

39

Extended Read . . .

SERIAL READ

A15

A14

A1

A0

C0

C5

C6

C7

x

8 bit CMD

16 bit Address

DATA[ADDR]

DATA[ADDR+1]

Extended Write . . .

SERIAL WRITE

D6

D1

D0

D7

D6

D1

D0

x

HI Z

HI Z

Status Byte

ST7

ST6

ST5

ST0

D7

40

47

0

31

15

16

23

24

32

39

40

47

Status Byte

D7

ST7

ST6

ST5

ST0

(From Host) SPI_CSZ

(From Host) SPI_CK

(From Host) SPI_DI

(From 654x) SPI_DO

Figure 27: SPI Slave Port - Typical Multi-Byte Read and Write operations

Table 63: SPI Command Sequences

Command Sequence

Description

ADDR 1xxx xxxx STATUS
Byte0 ... ByteN

Read data starting at ADDR. ADDR auto-increments until SPI_CSZ is
raised. Upon completion, SPI_CMD (SFR 0xFD) is updated to 1xxx xxxx
and an SPI interrupt is generated. The exception is if the command byte
is 1000 0000. In this case, no MPU interrupt is generated and SPI_CMD
is not updated.

0xxx xxxx ADDR Byte0 ...
ByteN

Write data starting at ADDR. ADDR auto-increments until SPI_CSZ is
raised. Upon completion, SPI_CMD is updated to 0xxx xxxx and an SPI
interrupt is generated. The exception is if the command byte is 0000
0000. In this case, no MPU interrupt is generated and SPI_CMD is not
updated.


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