LM8322 datasheet(21/42 Pages) NSC

21 / 42 page

14.8 END COMMAND

The END command terminates script execution and asserts

an interrupt to the host if the RESET bit is set to “1” or “0”.

If the END command is executed with the RESET bit set to

“1” , the PWM output will be disabled. If the RESET bit is “0”

when executing the END command, the PWM channel re-

mains active with the fixed duty cycle it was last set to.

Please note: If a PWM channel is waiting for the trigger (last

executed command was "TRIGGER") and the script execu-

tion is halted then the "END" command can’t be executed

because the previous command is still pending. This is an

exception - in this case the IRQ signal will not be asserted.

RESET

Bit

Value

Description

RESET

PWM_x output is active when script execution terminates.

PWM_x output is Tristate when script execution terminates.

14.9 TRIGGER COMMAND

Triggers are used to synchronize operations between PWM

channels. A TRIGGER command that sends a trigger takes

sixteen 32.768 kHz clock cycles, and a command that waits

for a trigger takes at least sixteen 32.768 kHz clock cycles.

A TRIGGER command that waits for a trigger (or triggers) will

stall script execution until the trigger conditions are satisfied.

Then, it will clear the trigger(s) and continue to the next com-

mand.

When a trigger is sent, it is stored by the receiving channel

and can only be cleared when the receiving channel executes

a TRIGGER command that waits for the trigger.

WAITTRIGGER

SENDTRIGGER

Field

Value

Description

0001xx

Wait for trigger from channel 2

WAITTRIGGER

000xx1

Wait for trigger from channel 0

000x1x

Wait for trigger from channel 1

SENDTRIGGER

000xx1

Send trigger to channel 0

000x1x

Send trigger to channel 1

0001xx

Send trigger to channel 2

14.10 PWM SCRIPT EXAMPLE

This example shows a complex ramping sequence that uses

triggers for synchronization. Three scripts implement the ex-

ample. Figure 14 shows the PWM outputs for this example.

30013614

FIGURE 14. PWM Outputs

LM8322 Arkusz danych(PDF) 21 Page - National Semiconductor (TI)

LM8322 Arkusz danych(HTML) 21 Page - National Semiconductor (TI)

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Arkusz danych Pobierz

Link URL