CLK Module
2-42
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The CLK_F_isr function causes the low-resolution time to be
incremented by 1.
❏
The CLK_F_isr function causes all the CLK Functions to be
performed in sequence in the context of that HWI.
Therefore, the low-resolution clock ticks at the timer interrupt rate and
returns the number of timer interrupts that have occurred. You can use
the CLK_getltime function to get the low-resolution time and the
CLK_getprd function to get the value of the period register property.
You can use GBL_setFrequency, CLK_stop, CLK_reconfig, and
CLK_start to change the low-resolution timer rate.
The low-resolution time is stored as a 32-bit value. Its value restarts at 0
when the maximum value is reached.
High-Resolution Time
The high-resolution time is determined as follows for your platform:
You can use the CLK_gethtime function to get the high-resolution time
and the CLK_countspms function to get the number of hardware timer
counter register ticks per millisecond.
The high-resolution time is stored as a 32-bit value. For platforms that
use the same timer counter as the low-resolution time, the 32-bit high-
resolution time is actually calculated by multiplying the low-resolution
time by the value of the PRD property and adding number of timer
counter increments or decrements (depending on your platform) since
the last timer counter reset.
The high-resolution value restarts at 0 when the maximum value is
reached.
Table 2-2.
High-Resolution Time Determination
Platform
Description
’C5501, ’C5502
A separate DSP/BIOS counter for the high-resolution time
runs at the following rate: CLKOUT / PLLDIV1. This timer
counter is stored in 64 bits.
’C5503, ’C5507,
’C5509, ’C5510,
’C5561
Number of times the timer counter has been decremented.
1x10 and 59xx
Number of times the timer counter has been decremented.
OMAP 2320
Number of times the timer counter has been incremented.
OMAP 2420
The value of Timer 7 running at 12 MHz. This value is
stored in 32 bits.