The code as follows. The function of Init_LF_125kHz is for initializing 125KHz. Manche_0_base for sending 52us 125KHz then staying low 52us (9600bps data). Manche_1_base for staying low 52us then sending 52us 125KHz.
Previous half cycle in the function of Manche_0_base or Manche_1_base and last half cycle in the interrupt function of LF_TX_HalfTdataInt.
#define MOD_125KHZ 0x00C0
#define HALFMOD_125KHZ 0x0060
void Init_LF_125kHz(void)
{
TPM1_MOD = MOD_125KHZ;
TPM1_C1SC = 0x24;
TPM1_C0SC = 0x28;
TPM1_C1V = HALFMOD_125KHZ;
TPM1_C0V = HALFMOD_125KHZ;
}
void Manche_0_base(void)
{
TPM1_SC = 0x88; //Output 125kHz, select TPM1 clock source = bus clock; TPM1 begins.
TPM2_SC = 0x88; //1 bit begin bus clock devided by 1
while(!(TPM2_SC & 0x80));
TPM2_SC = 0x80;//disable TPM2
}
void Manche_1_base(void)
{
Init_LF_125kHz();
TPM1_SC = 0x80; //No Output
TPM2_SC = 0x88; //1 bit begin
while(!(TPM2_SC & 0x80));
TPM2_SC = 0x80;//disable TPM2
TPM1_SC = 0x80; //125KHz end
}
/* TPM2ch0 ISR, interrupt occurred at the middle point of a bit */
void LF_TX_HalfTdataInt(void)
{
if(TPM1_SC & 0x08)
{ //Manchester 0
TPM1_SC = 0x80;
}
else
{ //Manchester 1
TPM1_SC = 0x88; //output 125KHz
}
TPM2_C0SC |= 0x80; //Clear CHF
}
