clvset

Command:	clvset
Contexts:	Network socket, serial console, stage2 only
Function:	Set up clocking parameters and ADC configuration for next readout
Required Parameters:	none.
Optional Parameters:
dev=	[current] Select dev 0 1 or all
id=	[0] (>=r5775) set up to 6 clocking patterns in controller memory at once
pg3=	8 sets of four hex digits to configure serial (row/horizontal) clocking
pg4=	8 sets of four hex digits to configure serial RESET, SUMMING WELL, (CCDs), VCLAMP, and ADCTRIG
ppg4=	8 sets of four hex digits to configure parallel (vertical) clocking
adc=	1 set of four hex digits plus an optional nibble to configure ADC operation
math=	Sequence of math processing operation codes to match adc=
mathcal=	Sequence resulting in separate 16 bit "pedestal" and "video" for "readcal"
trig=	Number of NOPs (10 nsec delay steps) to insert after each crosstrigger sync
pipeline=	Number of pipeline pixels resulting from clocking pattern (usually 1)
prescan=	Number of device serial prescan pixels to skip (clocked, but not sampled)
prebias=	Extra overscan pixels to be read after xtrig (usually 0)

Example

The following is a complete command to configure a typical "4+1" CCD clocking pattern on both clocking engines. It takes 4 samples of the pedestal level, plus 1 skipped for pipeline purposes, and then 4 samples of the video level, plus 1 skipped for pipeline purposes.

clvset dev=all ppg4=ecbb:cbb2:bb2e:65d8:5d97:38ba:6622:3154 \
               pg3=340e:40e0:1c03:c070:06c1:0417:649b:0136 \
               pg4=1038:8010:0104:00b0:07c2:0000:3732:08a2 \
               adc=1500:1 math=333301111A mathcal=1111A1111A

The command must be sent all on one line (or as multiple "clvset dev=all ..." commands - see section below.)

Parameter id=

This is a numeric parameter with a valid range of [0-5] inclusive. Only builds >= r5774 support this. This can be used to set up different speed clocking (parallel and serial) for different purposes. Eventually, other commands will support the id= parameter as well. This way one can quickly call up a previous clocking pattern without having to send all the other parameters each time. For now (as of r5775) the following IDs are hardcoded for the following uses:

id=0	Science readout
id=1	Video (e.g. guide cell) readout
id=2	OT or charge shuffling parallel shift operations

Note that build r5774 also supported the id feature, but builds < r5775 had a command line length limit of 256 bytes (increased to 2048 in r5775, with overflow detection.) The clvset commands, in particular, can become quite long because of the number of parameters. However, as long as the proper dev= and id= are always given, one can split the other parameters into as many lines/commands as desired.

Parameter adc=

The first, four-digit hex part of the adc= parameter is formed by or-ing several values together:

I | (C << 8) | (N << 10)

Where I (the lower 8 bits) specifies extra inter-sample delay time (usually left at 00), C is the number of channels (1 2 or 3) and N is the number of multiple samples to read each time ADCTRIG changes (goes high or low.)

The default behavior of the adc= parameter in single-sampled mode is to read only the "Red" ADC channel. All digits in the adc= parameter are in hex. The option last nibble after the colon allows one to select other ADC channels. It is a bit mask.

adc=1500	4+1 RED
adc=1500:1	4+1 RED
adc=1500:2	4+1 GREEN
adc=1500:4	4+1 BLUE

For two-channel mode, the following combinations are valid:

adc=1600	4+1 RED,GREEN
adc=1600:3	4+1 RED,GREEN
adc=1600:5	4+1 RED,BLUE
adc=1600:6	4+1 GREEN,BLUE

For three-channel mode, the mask is ignored and all three (RED, GREEN, BLUE) channels are active.

adc=1700

4+1 RED,GREEN,BLUE

Parameter math=

This is a string parameter, where each character of the string corresponds to one of the following operation codes:

0	(zero)Skip sample
1	Add sample to accumulator 1
2	Add sample to accumulator 2
3	Subtract sample from accumulator 1
4	Subtract sample from accumulator 2
A	Move accumulator 1 result to OCM and clear
B	Move accumulator 2 result to OCM and clear
C	Move sample directly to OCM (same memory as ACC1, typ. red channels)
D	Move sample directly to OCM (same memory as ACC2, typ. green channels)

The result of the accumulator that is moved into OCM is a 16 bit value obtained from the sum in the accumulator, plus an offset and divided by a divisor. The offset and divisor are automatically determined by the controller and cannot currently be set by the user. The divisor will be the number of Add operations in the specified math= pattern (i.e., a count of the 1 characters in the string).

The length of the string must match the number of samples requested in ADC= (per ADCTRIG), times TWO because there are two ADCTRIG events per pixel, times 1,2,or 3 depending on whether a single channel (e.g. "Red") or a set of channels (e.g. "Red+Green") is selected. The start of the pattern should match the "cestlavie" tool display. The controller rotates the pattern to the left by 3 positions to compensate for ADC pipeline delays that are intrinsic in the A/D part. Do not rotate the pattern string supplied to the controller.

Example for typical red-channel only, "4+1" sampling:

clvset adc=1500:1 math=333301111A mathcal=1111A1111A

Parameter mathcal=

If math= produces a result in OCM that includes both a 16-bit pedestal and a 16-bit video sample, then mathcal= is not needed. In cases where it only produces a single 16-bit value in OCM (i.e., the math sequence performs pedestal subtraction) then the pattern is not suitable for readcal. A separate pattern that is suitable can be provided with mathcal= which will only be used for the readcal command.