DS691A3

25

CS4350

MAP or the default address (see Section 6.4.2) if an I²C read is the first operation performed on the

device.

3.

Once the device has transmitted the contents of the register pointed to by the MAP, issue an ACK.

4.

If the INCR bit is set to 1, the device will continue to transmit the contents of successive registers.

Continue providing a clock and issue an ACK after each byte until all the desired registers are read;

then initiate a STOP condition to the bus.

5.

If the INCR bit is set to 0 and further I²C reads from other registers are desired, it is necessary to

initiate a repeated START condition and follow the procedure detailed from steps 1 and 2 from the I²C

Write instructions, followed by step 1 of the I²C Read section. If no further reads from other registers

are desired, initiate a STOP condition to the bus.

6.3

SPI Mode

In SPI Mode, data is clocked into the serial control data line, CDIN, by the serial control port clock, CCLK

(see Figure 17 for the clock to data relationship). There are no AD0 or AD1 pins. Pin CS is the chip select

signal and is used to control SPI writes to the control port. When the device detects a high-to-low transition

on the AD0/CS pin after power-up, SPI Mode will be selected. All signals are inputs and data is clocked in

on the rising edge of CCLK.

6.3.1

SPI Write

To write to the device, follow the procedure below while adhering to the control port switching specifica-

tions in ”Switching Characteristics - Control Port - SPI Format” on page 14.

1.

Bring CS low.

2.

The address byte on the CDIN pin must then be 10011110 (R/W =0).

3.

Write to the memory address pointer, MAP. This byte points to the register to be written.

4.

Write the desired data to the register pointed to by the MAP.

5.

If the INCR bit (see Section 6.1) is set to 1, repeat the previous step until all the desired registers are

written, then bring CS high.

6.

If the INCR bit is set to 0 and further SPI writes to other registers are desired, it is necessary to bring

CS high, and follow the procedure detailed from step 1. If no further writes to other registers are

desired, bring CS high

4

5

6

7

24 25

SCL

CHIP ADDRESS

MAP BYTE

DATA

DATA +1

START

ACK

STOP

ACK

ACK

ACK

1 0 0 1 0 AD1 AD0 R/W

SDA

6

5

4

3

2

1

0

7

6

1

0

7

6

1

0

7

6

1

0

0

1

2

3

8

9

12

16 17 18

19

10 11

13 14 15

27 28

26

DATA +n

INC

Figure 16. Control Port Timing, I²C Mode