LM8322EVALKIT National Semiconductor, LM8322EVALKIT Datasheet - Page 19

• Manufacturer Part Number: LM8322EVALKIT
• Description: BOARD EVALUATION LM8322
• Manufacturer: National Semiconductor

Specifications of LM8322EVALKIT

• Main Purpose: Interface, Special Purpose
• Embedded: No
• Utilized Ic / Part: LM8322
• Primary Attributes: Mobile I/O Companion with Key-Scan, I/O Expansion, PWM, Access.bus Host
• Secondary Attributes: Board has MCU for USB to PC GUI
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The period counter is a free running 8-bit up-counter which
starts counting when the script command file issues the first
RAMP command. An END command stops the period
counter.
The duty cycle of the PWM output is controlled by the ramp
counter. If the PWM period counter is active, the PWM output
signal is asserted while the period counter has a value less
than or equal to the value of the ramp counter.
The ramp counter can increment or decrement at a rate con-
trolled by the prescaler and step time counter. The prescaler
selects a factor of 16 or 512 for dividing down the frequency
SET_PWM
Command
TRIGGER
BRANCH
GO_TO_
START
RAMP
END
15
0
0
1
1
1
PRES
CALE
14
1
0
1
1
13
1
0
1
12
0
TABLE 8. PWM Script Commands
RESET
STEPTIME
11
FIGURE 13. PWM Timer
WAITTRIGGER
LOOPCOUNT
0
10
19
9
of the 32.768 kHz clock. The ramp counter saturates at either
0x00 or 0xFF depending on the ramp direction.
The number of increment or decrement steps is specified by
the INCREMENT field of the RAMP command, which is load-
ed into the step counter. Even if the ramp counter hits its
saturation value, the requested number of steps will be per-
formed. An option enables assertion of the IRQ output to the
host after the last step is performed.
14.3 PWM SCRIPT COMMANDS
Table 8 summarizes the script commands.
0
8
SIGN
7
6
0
0
5
SENDTRIGGER
PWMVALUE
INCREMENT
4
ADDRESS
3
30013613
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