Camera Link registers
17
Goldeye Camera Link Register Controls Reference V1.0.0
ReadMem Command Packet Layout
In order to read a camera register, the host has to issue a
ReadMem
command. The
command consists of a single packet that is described in the following tables.
Offset
[Bytes]
Size
[Bytes]
Name
Description
0
2
Preamble
Preamble that contains the bytes
0x01
and
0x00
.
2
2
CCD
Checksum
16 bit checksum that is built over the channel_id and the CCD of
the packet. Note that this is not a classic CRC calculation as
suggested by the standard! Refer to
Calculation Function on page 7-21
for more information.
4
2
SCD
Checksum
16 bit checksum that is built over channel_id, CCD and SCD of
the packet. Note that this is not a classic CRC calculation as
suggested by the standard! Please refer to
Calculation Function on page 7-21
for more information.
6
2
channel_id
This value is
0
for the control channel.
Table 3: ReadMem Command packet layout - Subrange: Serial prefix
Offset
[Bytes]
Size
[Bytes]
Name
Description
8
2
flags
Bit 0..13: reserved (= 0)
Bit 14:
RequestAck
(must be set if the sender commands an
acknowledge packet from the camera. This will usually be 1.)
Bit 15:
CommandResend
(This bit should be set, if the host did not
receive a valid reply to a previous command. In this case the
packet can be resent with this bit set.)
10
2
command_id
This value is 0x0800 for
ReadMem
commands.
12
2
length
Defines the length of the SCD part of the packet. For
ReadMem
commands, this value is
12
.
14
2
request_id
This is a packet identifier that should be incremented by the host
each time it issues a new command. If resending a packet, the
request_id should be the same as in the original packet.
Table 4: ReadMem Command packet layout - Subrange: CCD
Offset
[Bytes]
Size
[Bytes]
Name
Description
16
8
register
address
This is a 64 bit value defining the address to read from.
24
2
reserved
0
26
2
read length
This value defines the number of bytes to read from the desired
address. The GenCP Standard recommends requesting not more
than 1000 bytes.
Table 5: ReadMem Command packet layout - Subrange: SCD
