AT90PWM216-16SE ATMEL [ATMEL Corporation], AT90PWM216-16SE Datasheet - Page 158

• Manufacturer Part Number: AT90PWM216-16SE
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable flash
• Manufacturer: ATMEL [ATMEL Corporation]

16.18.2
16.18.3
158
AT90PWM216/316
Event Capture
Using the Input Capture Unit
Table 16-7.
The PSC can capture the value of time (PSC counter) when a retrigger event or fault event
occurs on PSC inputs. This value can be read by sofware in PICRnH/L register.
There are 2 ways to trigger a capture of the PSC counter in the PICRn Register.
The main challenge when using the Input Capture unit is to assign enough processor capacity
for handling the incoming events. The time between two events is critical. If the processor has
not read the captured value in the PICRn Register before the next event occurs, the PICRn will
be overwritten with a new value. In this case the result of the capture will be incorrect.
When using the Input Capture interrupt, the PICRn Register should be read as early in the inter-
rupt handler routine as possible. Even though the Input Capture interrupt has relatively high
priority, the maximum interrupt response time is dependent on the maximum number of clock
cycles it takes to handle any of the other interrupt requests.
Input Mode
Number :
6
7
8
9
10
11
12
13
14
15
– Hardware input capture triggered by a signal on PSC inputs.
– Software input capture triggered by the PCSTn bit
Available Input Modes according to Running Modes
1 Ramp Mode
Do not use
Valid
Valid
Valid
Do not use
Valid
Do not use
2 Ramp Mode
Valid
Valid
Valid
Valid
Valid
4 Ramp Mode
Valid
Valid
Valid
Valid
Valid
Centered Mode
Do not use
Valid
Do not use
Do not use
Do not use
7710D–AVR–08/09