GS6152 Datasheet, PDF (39/80 Pages) Semtech Corporation – Multi-Rate 6G UHD-SDI

4.11.10 Default GSPI Operation
By default at power up or after a device reset, the GS6152 is set for Loop-Through
Operation and the internal DEVICE_UNIT_ADDRESS field of the device is set to 0.
Figure 4-21 shows a functional block diagram of the Configuration and Status Register
(CSR) map in the GS6152 for non-extended memory accesses (EMEM = 0).
At power-up or after a device reset, DEVICE_UNIT_ADDRESS = 00h
bits
CMD
[15] [14]
[13] [12]
R/W
BCAST
ALL
EMEM
Auto
Inc
[11:7]
Unit Address
32 devices
bits
DATA
[15:0]
Data to be written / Read Data
[6:0]
Local Address
128 registers
Compare
bits
Reg 0
[15]
[14]
RESERVED
GSPI_LINK
_DISABLE
[13]
GSPI_BUS_
THROUGH
_ENABLE
[12:5]
RESERVED
[4:0]
DEVICE_UNIT_ADDRESS
Read/Write
Reg 1
Reg 128
Configuration and Status Registers
Figure 4-21: Internal Register Map Functional Block Diagram
The steps required for the application host processor to write to the Configuration and
Status Registers via the GSPI, are as follows:
1. Set Command Word for write access (R/W = 0) to the local registers 0h-80h; set Auto
Increment; set the Unit Address field in the Command Word to match the
configured DEVICE_UNIT_ADDRESS which will be zero. Write the Command Word.
2. Write the Data Word to be written to the first register.
3. Write the Data Word to be written to the next register in Auto Increment mode, etc.
Read access is the same as the above with the exception of step 1, where the Command
Word is set for read access (R/W = 1).
Note: The UNIT ADDRESS field of the Command Word must always match
DEVICE_UNIT_ADDRESS for an access to be accepted by the device. Changing
DEVICE_UNIT_ADDRESS to a value other than 0 is only required if multiple devices are
connected to a single chip select (in Loop-Through or Bus-Through configuration.)
GS6152
Final Data Sheet
PDS-060984
Rev.2
July 2015
www.semtech.com
39 of 80
Semtech
Proprietary & Confidential