GS3140 Datasheet, PDF (23/40 Pages) Semtech Corporation – Multi-Rate Adaptive 3G SDI Equalizer

4.11.5.4 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.
The internal address is incremented for each 16-bit read or write access until a
low-to-high transition on the CS pin is detected.
When AUTOINC is set to 0, single read or write access is required.
Auto-Increment write must not be used to update values in HOST_CONF_REG_0.
4.11.5.5 UNIT ADDRESS - B11:B7 Command Word
The 5 bits of the UNIT ADDRESS field of the Command Word are used to select one of 32
devices connected on a single chip select in Loop-Through or Bus-Through
configurations.
Read and write accesses are only accepted if the UNIT ADDRESS field matches the
programmed DEVICE_UNIT_ADDRESS in HOST_CONF_REG_0
By default at power-up or after a device reset, the DEVICE_UNIT_ADDRESS is set to 00_h
4.11.5.6 ADDRESS - B6:B0 Command Word
The 7 bits of the ADDRESS field are used to select one of the register addresses in the
device in single read or write access mode, or to set the starting address for read or write
accesses in Auto-Increment Mode.
Command Word
MSB
UNIT ADDRESS
LSB
ADDRESS
R/W
B’CAST
ALL
EMEM AUTOINC
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
Data Word
7-bit CSR address field providing up to
128 configuration registers.
5-bit UNIT ADDRESS field providing up to
32 devices to be connected on a single CS.
Auto increment read/write access when set.
Single read write access when reset.
Extended memory mode. When set, the extended memory mode is
enabled. When reset, normal GSPI addressing is enabled (EMEM
is not enabled in the GS3140).
When set, the UNIT ADDRESS field is ignored and
all data accesses are actioned by the device.
When reset, the Unit Address is used to
manage data accesses in the device.
Read access when this bit is set.
Write access when this bit is reset.
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Figure 4-6: Command and Data Word Format
GS3140
Final Data Sheet
PDS-060939
Rev.1
May 2015
www.semtech.com
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