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i2c: set high and low times to values that conform to the i2c specification (#314)

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Brian Cooke
2021-04-09 12:00:33 +02:00
committed by GitHub
parent 4fe995d0ec
commit f69f513a29
1 changed files with 2 additions and 2 deletions
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4
src/rp2_common/hardware_i2c/i2c.c
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@ -67,8 +67,8 @@ uint i2c_set_baudrate(i2c_inst_t *i2c, uint baudrate) {
// TODO there are some subtleties to I2C timing which we are completely ignoring here // TODO there are some subtleties to I2C timing which we are completely ignoring here
uint period = (freq_in + baudrate / 2) / baudrate; uint period = (freq_in + baudrate / 2) / baudrate;
uint hcnt = period * 3 / 5; // oof this one hurts uint lcnt = period * 3 / 5; // oof this one hurts
uint lcnt = period - hcnt; uint hcnt = period - lcnt;
// Check for out-of-range divisors: // Check for out-of-range divisors:
invalid_params_if(I2C, hcnt > I2C_IC_FS_SCL_HCNT_IC_FS_SCL_HCNT_BITS); invalid_params_if(I2C, hcnt > I2C_IC_FS_SCL_HCNT_IC_FS_SCL_HCNT_BITS);
invalid_params_if(I2C, lcnt > I2C_IC_FS_SCL_LCNT_IC_FS_SCL_LCNT_BITS); invalid_params_if(I2C, lcnt > I2C_IC_FS_SCL_LCNT_IC_FS_SCL_LCNT_BITS);