Instruction manual

10 GB Communication

Version

1.0

& Control Card Instruction Manual

4.10 CAM Timer

The CAM Timer unit is for generating 4-channel timing pulses on the

EIO Connector. Timing pulses are produced by 10 identical timers, each

capable of generating a sequence of pulses. Each timer has 4 individually

adjustable parameters: delay time (32 bits) of the sequence, on-time 16

bits), off-time (16 bits) and number of pulses (28 bits). The Timer

parameters can be programmed by the SETCTTIMER instruction.

Figure 8. Timer parameters

The output of these timers can be combined to 4 output pulse

sequences. Each timer can be OR connected to any of the four outputs and

they can be enabled independently. The first 4 bits (bit 31 downto 28) of the

32-bit Number Of Pulses parameter in the SETCTTIMER instruction are the

channel enable bits. The timing output parameters can be set by the

SETCTOUTPUT instruction.

The reference clock signal of the timers is generated from the internal

20 MHz system clock divided by a programmable value (2 bytes giving a

maximum division of 64K). This divided clock serves as the base clock for all

the internal timers. The divider value can be programmed by the

SETCTCLKDIV instruction.

The CAM Timer can be in one of three states: idle, armed or running.

Idle is the default state after power-up, when the unit does not respond to

trigger and does not produce output pulses. This state is normally used for

setting up operation parameters. After programming is finished CAM Timer is

set to armed state by setting bit 0 in the CAM Timer Control register. In this

state the unit waits for trigger, still no timing pulses are generated. From

armed state running state is entered on a trigger edge or when a start

command is received (bit 1 of the CAM Timer Control register is set). Pulse

generation starts from this time instance. Operation can be aborted by

software command (clearing bit 0 or bit 1 in the CAM Timer Control register)

or it ends when all 10 timers finished generating the requested number of

pulses. Bits 2 and 3 in the CAM Timer Control register control the action to