CS4382 Datasheet, PDF (30/42 Pages) Cirrus Logic – 114 dB, 192 kHz 8-Channel D/A Converter

CS4382
6.4 SPI Format
In SPI format, CS is the CS4382 chip select signal,
CCLK is the control port bit clock, CDIN is the in-
put data line from the microcontroller and the chip
address is 0011000. CS, CCLK and CDIN are all
inputs and data is clocked in on the rising edge of
CCLK.
Note that the CS4382 is write-only when in SPI
format.
6.4.1 Writing in SPI
Figure 8 shows the operation of the control port in
SPI format. To write to a register, bring CS low.
The first 7 bits on CDIN form the chip address and
must be 0011000. The eighth bit is a read/write in-
dicator (R/W), which must be low to write. The
next 8 bits form the Memory Address Pointer
(MAP), which is set to the address of the register
that is to be updated. The next 8 bits are the data
which will be placed into register designated by the
MAP. To write multiple registers, keep CS low and
continue providing clocks on CCLK. End the read
transaction by setting CS high.
SDA
ADDR
001100 _AD0
R /W A C K
N ote 1
DATA
1-8
ACK
DATA
1-8
ACK
SCL
S ta rt
S top
N o te : If o p e ra tio n is a w rite , th is b y te c o n ta in s th e M e m o ry A d d re s s P o in te r, M A P .
Figure 7. Control Port Timing, I²C Format
CS
C C LK
C D IN
C H IP
ADDRESS
0011000
R /W
MAP
DATA
M SB
LSB
b y te 1
b y te n
M A P = M e m o ry A d d re s s P o in te r
Figure 8. Control Port Timing, SPI Format
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