Hi,
I have question about AM335x DMTIMER.
My customer are using DMTIMER6 to generate PWM pulse(4096Hz or 4219Hz)
Case 1: generate 4096Hz
When they use CLK_32KHz as DMTIMER clock source and configure the DMTIMER register as following,
4096Hz was output successfully.
/////////////////////////////////////////////////////////////////////////
CLKSEL_TIMER6_CLK = 0x00000002 //select CLK_32KHz
CM_PER_TIMER6_CLKCTRL = 0x00000002 //Enable
TIMER6_TCLR = 0x00000040 // PT=0,TRG=0,SCPWM=0,CE=1,PRE=0,PTV=0,AR=0,ST=0
TIMER6_TMAR = 0xFFFFFFFB
TIMER6_TLDR = 0xFFFFFFF8
TIMER6_TTGR = 0x00000000
/////////////////////////////////////////////////////////////////////////
Case 2: generate 4219Hz
But when they use CLK_M_OSC(24MHz) as DMTIMER clock source and configure the DMTIMER register as following,
they don't know why but it output about 32KHz.
/////////////////////////////////////////////////////////////////////////
CLKSEL_TIMER6_CLK = 0x00000001 //select CLK_M_OSC(24MHz)
CM_PER_TIMER6_CLKCTRL = 0x00000002 //Enable
TIMER6_TCLR = 0x00000068 //PT=0,TRG=0,SCPWM=0,CE=1,PRE=1,PTV=010,AR=0,ST=0
TIMER6_TMAR = 0xFFFFFE9C
TIMER6_TLDR = 0xFFFFFD39
TIMER6_TTGR = 0x00000000
/////////////////////////////////////////////////////////////////////////
In case 2, I guess register configuration is fine.
From the configuration value of TCLR.PRE, TCLR.PTV, TLDR, I guess about 4220Hz should be generated.
If the register configurations are mistaken, can you please tell me.
best regards,
g.f.
