GS6150 Datasheet, PDF (36/64 Pages) Gennum Corporation – Automatic or Manual Rate Selection

4.11.7 Single Read/Write Access
Single read/write access timing for the GSPI interface is shown in Figure 4-11 to
Figure 4-15.
When performing a single read or write access, one Data Word is read from/written to
the device per access. Each access is a minimum of 32-bits long, consisting of a
Command Word and a single Data Word. The read or write cycle begins with a high-to-
low transition of the CS pin. The read or write access is terminated by a low-to-high
transition of the CS pin.
The maximum interface clock rate is 27MHz and the inter-command delay time
indicated in the figures as t_cmd, is a minimum of 4 SCLK clock cycles. After modifying
values in HOST_CONFIG, the inter-command delay time, t_{cmd_GSPI_config}, is a minimum
of 5 SCLK clock cycles.
For read access, the time from the last bit of the Command Word to the start of the data
output, as defined by t₅, corresponds to no less than 5 SCLK clock cycles at 27MHz.
SCLK
CS
t_cmd
SDIN
COMMAND
DATA
X
COMMAND
SDOUT
COMMAND
DATA
X
COMMAND
Figure 4-11: GSPI Write Timing – Single Write Access with Loop-Through Operation (default)
SCLK
CS
t_cmd
SDIN
COMMAND
DATA
X
COMMAND
SDOUT
Figure 4-12: GSPI Write Timing – Single Write Access with GSPI Link-Disable Operation
SCLK
CS
t_cmd
SDIN
High-Z
SDOUT
COMMAND
COMMAND
DATA
DATA
X
High-z
COMMAND
COMMAND
Figure 4-13: GSPI Write Timing – Single Write Access with Bus-Through Operation
GS6150
Final Data Sheet
PDS-060127
Rev.2
March 2015
www.semtech.com
36 of 64
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