SPI Port
CS4953xx Hardware Users Manual
DS732UM7
Copyright 2008 Cirrus Logic, Inc
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able to receive more data words, the SCP1_BSY signal will go high. Once the SCP1_BSY signal is high,
proceed to Step 3.
6.
The master finishes the SPI write transaction by driving the CS4953xx SCP1_CS signal high.
3.3.3.3 Performing a Serial SPI Read
Information provided in this section is intended as a functional description indicating how an external device
(Master) performs an SPI read from the CS4953xx (slave). The system designer must ensure that all timing
constraints of the SPI read cycle are met (see the CS4953xx datasheet for timing specifications).
When performing a SPI read, the same protocol is used whether reading a single byte or multiple bytes. From a
hardware perspective, it makes no difference whether communication is a single byte or multiple bytes of any
message length, so long as the correct hardware protocol is followed. The example shown in this section can be
generalized to fit any SPI read situation.
, illustrates the sequence of events that define the SPI read protocol. The
Serial SPI read protocol is described in
.
Figure 3-17. SPI Read Flow Diagram
SCP1_IRQ
(LOW)?
SCP1_IRQ STILL
LOW?
SCP1_CS HIGH
Y
N
Y
N
START
SCP1_CS LOW
READ 4 DATA BYTES
WRITE ADDRESS BYTE
0x81
Содержание CS4953xx
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