OMAP 2420 and the CLK Module
DSP/BIOS for OMAP 2420
D-3
❏
ENABLECLK.
For OMAP 2420, this property enables/disables only
the low-resolution timer. For example, these statements disable the
low-resolution clock:
bios.PRD.USECLK = false;
bios.CLK.ENABLECLK = false;
❏
ENABLEHTIME.
For OMAP 2420, this property enables/disables the
high-resolution clock independent of the low-resolution clock. For
example:
bios.CLK.ENABLEHTIME = false;
D.2.2
GEL Configuration
In order for the DSP to access the GP timers, you must configure the
DSP MMU to map the GP timers into the DSP address space. This can
be done using the following ARM-side GEL commands (which are also
provided with CCStudio) or dedicated ARM code.
hotmenu ProgramMMU()
{
/* DSP MMU_SYSCONFIG - Set bit 1 to perform a SOFTRESET */
*(int *)0x5A000010 |= 0x2;
/* TLB 0 - GPTIMER5 = 0x7000, Big Endian */
*(int *)0x5A000050 = 0x00000000; /* DSP MMU_LOCK */
*(int *)0x5A000058 = 0x00fdc00e; /* DSP MMU_CAM */
*(int *)0x5A00005C = 0x4807c340; /* DSP MMU_RAM */
*(int *)0x5A000054 = 0x00000001; /* DSP MMU_LD_TLB */
/* TLB 1 - GPTIMER6 = 0x7400, Big Endian */
*(int *)0x5A000050 = 0x00000010; /* DSP MMU_LOCK */
*(int *)0x5A000058 = 0x00fdd00e; /* DSP MMU_CAM */
*(int *)0x5A00005C = 0x4807e340; /* DSP MMU_RAM */
*(int *)0x5A000054 = 0x00000001; /* DSP MMU_LD_TLB */
/* TLB 2 - GPTIMER7 = 0x7c00, Big Endian */
*(int *)0x5A000050 = 0x00000020; /* DSP MMU_LOCK */
*(int *)0x5A000058 = 0x00fde00e; /* DSP MMU_CAM */
*(int *)0x5A00005C = 0x48080340; /* DSP MMU_RAM */
*(int *)0x5A000054 = 0x00000001; /* DSP MMU_LD_TLB */
/* disable TLB updates, disable TWL, enable MMU */
*(int*)0x5a000044 = 0x02;
}