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Standard Functionality, SCKP (Pin 45) = High, Operation = Read

MSB

A4 A3 A2 A1 A0

(Address)

CLK CLK

1

2

CLK

6

CLK

7

CLK

16

CLK

17

CLK

18

CLK

19

CLK

23

CLK

24

CLK

32

MSB

D9–D0 LSB

DATA_REQUEST

(16 Bits)

D9–D0

(Data)

LSB

D15–D10

DATA_SEND

(16 Bits)

SLOAD

SCLK

SDIN

SDO

VSP1221

SLES012A – SEPTEMBER 2001 – REVISED JULY 2004

Figure 5. Serial Interface Timing for Read, SCKP = High

Device register values can be read back serially from the SDO pin (pin 1). For serial data read, user first sends a

16 bit DATA_REQUEST on the SDIN pin (pin 47). The format is as follows:

DATA_REQUEST on SDIN

SD15

SD14-SD10

SD9-SD0

1

Required register address

Don't Care

Although the length of DATA_REQUEST is 16 bits, the ten LSBs are don't cares. Also, note that SD15 (RD/WR)

should be 1 for register read (see the serial data format section). The register address portion of

DATA_REQUEST is decoded and the register data value (DATA_SEND) is available on the SDO pin at the rising

edge of CLK18 (see Figure 5) if SLOAD is low at that time. If SLOAD is high at that time, then DATA_SEND is

available when SLOAD goes low again. The format of DATA_SEND is as follows:

DATA_SEND on SDO

SD15-SD10

SD9-SD0

Don't Care

Required register data

Although the length of DATA_SEND is 16 bits, the six MSBs are don't cares.

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