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SPI SERIAL CONTROL PORT FOR MODE CONTROL

MSB

0

IDX6

IDX5

IDX4

IDX3

IDX2

IDX1

IDX0

D7

D6

D5

D4

D3

D2

D1

D0

0

0

LSB

Register Index (or Address)

Register Data

R0001-01

IDX0

D7

D6

D4

D5

D3

D2

D1

D0

0

MS

MC

MD

X

0

IDX6

X

IDX1

IDX2

IDX3

IDX4

IDX5

IDX6

X

T0048-03

PCM1807

SLES147 – SEPTEMBER 2005

The user-programmable built-in functions of the PCM1807 can be controlled through the serial control port with

SPI format. All operations for the serial control port use 16-bit data words. Figure 28 shows the control data word

format. The most-significant bit must be set to 0. Seven bits, labeled IDX[6:0], set the register index (or address)

for the write operations. The least-significant eight bits, D[7:0], contain the data to be written to the register

specified by IDX[6:0].

Figure 29 shows the functional timing diagram for writing to the serial control port. MS (pin 12) is held at a logic-1

state until a register is to be written. To start the register write cycle, MS is set to logic-0. Sixteen clocks are then

provided on MC (pin 11), corresponding to the 16 bits of the control data word on MD (pin 10). After the 16th

clock cycle has completed, the data is latched into the indexed-mode control register in the write operation. To

write subsequent data, MS must be set to 1 once.

Figure 28. Control Data Word Format for MD

Figure 29. Serial Control Format

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