bilbo/saturn
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

correct smpc intback timing

Browse Source
This commit is contained in:
Zack Buhman 2023-01-09 18:07:33 -08:00
parent 76c4998664
commit fe51d016df
1 changed files with 18 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
main.c
View File

@ -19,6 +19,19 @@ void timer0_int(void)
scu.reg.IST &= ~(IST__TIMER0);
}
void v_blank_in_int(void) __attribute__ ((interrupt_handler));
void v_blank_in_int(void)
{
scu.reg.IST &= ~(IST__V_BLANK_IN);
// reset FRC to zero
sh2.reg.FRC.H = 0;
sh2.reg.FRC.L = 0;
// enable output compare interrupt
sh2.reg.TIER = TIER__OCIAE;
}
void oci_int(void) __attribute__ ((interrupt_handler));
void oci_int(void)
{
@ -37,6 +50,9 @@ void oci_int(void)
smpc.reg.IREG2 = INTBACK__IREG2__MAGIC;
smpc.reg.COMREG = COMREG__INTBACK;
// disable output compare interrupt (to be re-enabled on the next v_blank_in)
sh2.reg.TIER = 0;
}
void smpc_int(void) __attribute__ ((interrupt_handler));
@ -44,8 +60,6 @@ void smpc_int(void)
{
scu.reg.IST &= ~(IST__SMPC);
smpc.reg.IREG0 = INTBACK__IREG0__BREAK;
}
@ -198,6 +212,7 @@ void start(void)
vec[SCU_VEC__TIMER0] = (u32)(&timer0_int);
vec[SCU_VEC__SMPC] = (u32)(&smpc_int);
vec[SCU_VEC__V_BLANK_IN] = (u32)(&v_blank_in_int);
//scu.reg.T0C = 5;
//scu.reg.T1MD = T1MD__TENB;
@ -235,16 +250,10 @@ void start(void)
// we are required to write the upper bit prior to
// writing the lower byte
sh2.reg.OCRAB.L = 63;
sh2.reg.FRC.H = 0;
sh2.reg.FRC.L = 0;
// enable output compare interrupt
sh2.reg.TIER = TIER__OCIAE;
// reset/enable interrupts
scu.reg.IST = 0;
scu.reg.IMS = ~(IMS__SMPC);
scu.reg.IMS = ~(IMS__SMPC | IMS__V_BLANK_IN);
while (1) {
vec[0] = scu.reg.IST;