GV7704 Datasheet, PDF (31/52 Pages) Semtech Corporation – Quad HD-VLC Receiver

For read operations, the SDOUT pin is used to output data read from an internal
Configuration and Status Register (CSR) when CS is LOW. Data is shifted out of the
device on the falling edge of SCLK, so that it can be read by the host processor on the
subsequent SCLK rising edge. The current drive strength of the SDOUT pin can be
adjusted using the GSPI_SDOUT_DRV_STRENGTH_SEL bit.
4.9.4 SCLK Pin
The SCLK pin is the GSPI serial data shift clock input to the device, and must be provided
by the host processor.
Serial data is clocked into the GV7704 SDIN pin on the rising edge of SCLK. Serial data is
clocked out of the device from the SDOUT pin on the falling edge of SCLK (read
operation). SCLK is ignored when CS is HIGH.
4.9.5 Command Word Description
All GSPI accesses are a minimum of 48 bits in length (a 16-bit Command Word, a 16-bit
Extended Address field, and a 16-bit Data Word) and the start of each access is indicated
by the HIGH-to-LOW transition of the chip select (CS) pin of the GV7704.
The format of the Command Word and Data Words are shown in Figure 4-13.
Data received immediately following this HIGH-to-LOW transition will be interpreted as
a new Command Word.
4.9.5.1 R/W bit - B15 Command Word
This bit indicates a read or write operation.
When R/W is set to 1, a read operation is indicated and data is read from the register
specified by the ADDRESS field of the Command Word.
When R/W is set to 0, a write operation is indicated and data is written to the register
specified by the ADDRESS field of the Command Word.
4.9.5.2 BROADCAST ALL - B14 Command Word
This bit must always be set to 0.
4.9.5.3 EMEM - B13 Command Word
This bit must always be set to 1.
4.9.5.4 AUTOINC - B12 Command Word
When AUTOINC is set to 1, Auto-Increment read or write access is enabled.
In Auto-Increment Mode, the device automatically increments the register address for
each contiguous read or write access, starting from the address defined in the ADDRESS
field of the Command Word.
GV7704
Preliminary Data Sheet Rev.3
PDS-060376
September 2015
www.semtech.com
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Semtech