CLK Module
2-46
❏
Clock Rate to ltime timer
. Specify the rate in MHz for the low-
resolution time. On the OMAP 2420, this may be either the 0.032
MHz clock, the 12 MHz clock, or the external clock. (OMAP 2420
only.)
Tconf Name: INPUTCLK
Type: Numeric
Example:
bios.CLK.INPUTCLK = 0.032;
❏
Clock Rate to htime timer
. Specify the rate in MHz for the high-
resolution time. On the OMAP 2420, this may be either the 0.032
MHz clock, the 12 MHz clock, or the external clock. (OMAP 2420
only.)
Tconf Name: HTIMECLK
Type: Numeric
Example:
bios.CLK.HTIMECLK = 12.0;
❏
Instructions/Int
. The number of instruction cycles represented by
the period specified above. This is an informational property only.
Tconf Name: N/A
CLK Object Properties
The Clock Manager allows you to create an arbitrary number of CLK
objects. Clock objects have functions, which are executed by the Clock
Manager every time a timer interrupt occurs. These functions can invoke
any DSP/BIOS operations allowable from within an HWI except
HWI_enter or HWI_exit.
To create a CLK object in a configuration script, use the following syntax:
var myClk = bios.CLK.create("myClk");
The following properties can be set for a clock function object in the CLK
Object Properties dialog in the DSP/BIOS Configuration Tool or in a
Tconf script. The Tconf examples assume the myClk object has been
created as shown.
❏
comment
. Type a comment to identify this CLK object.
Tconf Name: comment
Type: String
Example:
myClk.comment = "Runs timeFxn";
❏
function
. The function to be executed when the timer hardware
interrupt occurs. This function must be written like an HWI function; it
must be written in C or assembly and must save and restore any
registers this function modifies. However, this function can not call
HWI_enter or HWI_exit because DSP/BIOS calls them internally
before and after this function runs.
These functions should be very short as they are performed
frequently.