diff options
Diffstat (limited to 'nuttx/arch/mips/src/pic32mx/pic32mx-timerisr.c')
| -rwxr-xr-x | nuttx/arch/mips/src/pic32mx/pic32mx-timerisr.c | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/nuttx/arch/mips/src/pic32mx/pic32mx-timerisr.c b/nuttx/arch/mips/src/pic32mx/pic32mx-timerisr.c index 1ef888d4e..906ec0cc4 100755 --- a/nuttx/arch/mips/src/pic32mx/pic32mx-timerisr.c +++ b/nuttx/arch/mips/src/pic32mx/pic32mx-timerisr.c @@ -59,28 +59,28 @@ * Definitions ****************************************************************************/ /* Timer Setup **************************************************************/ -/* Select a timer prescale value. Our goal is to select the timer MATCH - * register value givent the board's periperhal clock frequency and the - * desired system timer frequency: +/* Select a timer 1 prescale value. Our goal is to select the timer MATCH + * register value given the board's SOSC clock frequency and the desired + * system timer frequency: * - * TIMER1_MATCH = BOARD_PBCLOCK / TIMER1_PRESCALE / CLOCKS_PER_SEC + * TIMER1_MATCH = BOARD_SOSC_FREQ / TIMER1_PRESCALE / CLOCKS_PER_SEC * * We want the largest possible value for MATCH that is less than 65,535, the * maximum value for the 16-bit timer register: * - * TIMER1_PRESCALE >= BOARD_PBCLOCK / CLOCKS_PER_SEC / 65535 + * TIMER1_PRESCALE >= BOARD_SOSC_FREQ / CLOCKS_PER_SEC / 65535 * * Timer 1 does not have very many options for the perscaler value. So we * can pick the best by brute force. Example: * - * BOARD_PBCLOCK = 40000000 + * BOARD_SOSC_FREQ = 32768 * CLOCKS_PER_SEC = 100 - * OPTIMAL_PRESCALE = 6 - * TIMER1_PRESCALE = 8 - * TIMER1_MATCH = 50,000 + * OPTIMAL_PRESCALE = 1 + * TIMER1_PRESCALE = 1 + * TIMER1_MATCH = 328 -> 99.90 ticks/sec */ -#define OPTIMAL_PRESCALE (BOARD_PBCLOCK / CLOCKS_PER_SEC / 65535) +#define OPTIMAL_PRESCALE (BOARD_SOSC_FREQ / CLOCKS_PER_SEC / 65535) #if OPTIMAL_PRESCALE <= 1 # define TIMER1_CON_TCKPS TIMER1_CON_TCKPS_1 # define TIMER1_PRESCALE 1 @@ -97,7 +97,7 @@ # error "This timer frequency cannot be represented" #endif -#define TIMER1_MATCH (BOARD_PBCLOCK / TIMER1_PRESCALE / CLOCKS_PER_SEC) +#define TIMER1_MATCH (BOARD_SOSC_FREQ / TIMER1_PRESCALE / CLOCKS_PER_SEC) /**************************************************************************** * Private Types @@ -143,7 +143,7 @@ int up_timerisr(int irq, uint32_t *regs) void up_timerinit(void) { - /* Configure and enable TIMER1 -- source internal (TCS=0) */ + /* Configure and enable TIMER1 -- source internal SOSC (TCS=0) */ putreg32(TIMER1_CON_TCKPS, PIC32MX_TIMER1_CON); putreg32(0, PIC32MX_TIMER1_CNT); |