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n, h and l actually are 6-bit; they go from 1 to 64.

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Jeroen Domburg 2017-01-11 14:13:37 +08:00
parent a98d07d650
commit daa2b7cbc9
1 changed files with 2 additions and 2 deletions
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4
components/driver/spi_master.c
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@ -396,7 +396,7 @@ static int spi_freq_for_pre_n(int fapb, int pre, int n) {
static void spi_set_clock(spi_dev_t *hw, int fapb, int hz, int duty_cycle) { static void spi_set_clock(spi_dev_t *hw, int fapb, int hz, int duty_cycle) {
int pre, n, h, l; int pre, n, h, l;
//In hw, n, h and l are 1-32, pre is 1-8K. Value written to register is one lower than used value. //In hw, n, h and l are 1-64, pre is 1-8K. Value written to register is one lower than used value.
if (hz>((fapb/4)*3)) { if (hz>((fapb/4)*3)) {
//Using Fapb directly will give us the best result here. //Using Fapb directly will give us the best result here.
hw->clock.clkcnt_l=0; hw->clock.clkcnt_l=0;
@ -414,7 +414,7 @@ static void spi_set_clock(spi_dev_t *hw, int fapb, int hz, int duty_cycle) {
int bestpre=-1; int bestpre=-1;
int besterr=hz; int besterr=hz;
int errval; int errval;
for (n=1; n<33; n++) { for (n=1; n<=64; n++) {
//Effectively, this does pre=round((fapb/n)/hz). //Effectively, this does pre=round((fapb/n)/hz).
pre=((fapb/n)+(hz/2))/hz; pre=((fapb/n)+(hz/2))/hz;
if (pre<0) pre=0; if (pre<0) pre=0;