47
the entire array if the Continuous Array Read flash command is used. All arguments are
ASCII hex. The exact syntax of the Read Flash command is:
'M' <opcode> <addr> <cmd_len> <data_len> <cr>
where opcode is one byte (2 hex digits), addr is 3 bytes (6 hex digits), cmd_len is one byte
(2 hex digits), and data_len is four bytes (8 hex digits). Most commands send the
<opcode> and <addr> bytes to the flash and then require some number of "don't care"
bytes before starting to read data from the flash. The only exception is the status read
command which sends only the command byte and has no additional turn-around delay.
When sending the status read command the <addr> bytes are "don't care", but must be
included in the command arguments. The following opcodes are acceptable to use with
this command (there is no error checking so make sure these are the only codes used).
Opcode Command
Command Length
D4
Buffer 1 read
5
D6
Buffer 2 read
5
E8
Continuous array read
8
D2
Main Memory Page Read 8
D7
Status Register Read
1
This is the only Control FPGA response that uses binary encoded arguments (with escape
codes for <cr> and \).
The camera responds with "M" followed by escaped binary data from the flash and finally a
non-escaped carriage-return. Internally the Control FPGA waits for the flash to become
non-busy then starts the flash read operation. Thus the Status Register Read command is
only useful to check the compare flag, since the busy flag will always be off.
S
ET
C
AMERA
S
TATE
This command takes a two byte (4 hex digit) offset into the current camera state as defined
in Table 4 and from one to to 512 bytes (2 to 1024 hex digits) of camera state data. The
exact syntax of the Set Camera State command is:
