Cheetah KAC Camera User Manual | Camera Link (CLF) Interface
October 1, 2019
Page
36
of
135
Rev 7.2
Figure 24: Serial protocol format.
Each camera control register can be updated independently. In terms of the serial
protocol, all registers are defined as 16-bit address (hex format), and 32-bit data (hex
format). Camera registers using less than 32-bits in width must be padded with ‘0’s on
writes, and unused bits are ignored on reads. Register data is always “packed low” within
32-bit data words for registers defined less than 32-bits.
There is a latency delay for each command due to command execution and data
transmission over the serial port. This latency varies from command to command because
of resource location and command response length.
3.1.3 Write Operation
In order to write to any given camera register, a sequence of 7 bytes should be sent to the
camera. If there is no error the camera returns one byte acknowledge for the write
command <Ack>. If there is an error the camera returns two bytes not-acknowledge for
the write command – the first byte is <Nac> <Err>, the second is the error code:
Write to camera (7 Bytes): <Write_Cmd> <
Address
> <
Data
>
1
st
byte: 0x57 (Write Command)
2
nd
byte:
<
Register Address_High
> MSB
3
rd
byte:
<
Register Address_Low
> LSB
4
th
byte:
<
Register Data Byte 4
> MSB
5
th
byte:
<
Register Data Byte 3
> …
6
th
byte:
<
Register Data Byte 2
> …
7
th
byte:
<
Register Data Byte 1
> LSB
Write Acknowledge (1 Byte): <Ack>
1
st
byte: 0x06 (Acknowledge)
