NanoVNA/si5351.c
2019-07-25 06:23:27 +09:00

397 lines
12 KiB
C

/*
* Copyright (c) 2014-2015, TAKAHASHI Tomohiro (TTRFTECH) edy555@gmail.com
* All rights reserved.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* The software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "hal.h"
#include "si5351.h"
#define SI5351_I2C_ADDR (0x60<<1)
static void
si5351_write(uint8_t reg, uint8_t dat)
{
int addr = SI5351_I2C_ADDR>>1;
uint8_t buf[] = { reg, dat };
i2cAcquireBus(&I2CD1);
(void)i2cMasterTransmitTimeout(&I2CD1, addr, buf, 2, NULL, 0, 1000);
i2cReleaseBus(&I2CD1);
}
static void
si5351_bulk_write(const uint8_t *buf, int len)
{
int addr = SI5351_I2C_ADDR>>1;
i2cAcquireBus(&I2CD1);
(void)i2cMasterTransmitTimeout(&I2CD1, addr, buf, len, NULL, 0, 1000);
i2cReleaseBus(&I2CD1);
}
// register addr, length, data, ...
const uint8_t si5351_configs[] = {
2, SI5351_REG_3_OUTPUT_ENABLE_CONTROL, 0xff,
4, SI5351_REG_16_CLK0_CONTROL, SI5351_CLK_POWERDOWN, SI5351_CLK_POWERDOWN, SI5351_CLK_POWERDOWN,
2, SI5351_REG_183_CRYSTAL_LOAD, SI5351_CRYSTAL_LOAD_8PF,
// setup PLL (26MHz * 32 = 832MHz, 32/2-2=14)
9, SI5351_REG_26_PLL_A, /*P3*/0, 1, /*P1*/0, 14, 0, /*P3/P2*/0, 0, 0,
// RESET PLL
2, SI5351_REG_177_PLL_RESET, SI5351_PLL_RESET_A | SI5351_PLL_RESET_B,
// setup multisynth (832MHz / 104 = 8MHz, 104/2-2=50)
9, SI5351_REG_58_MULTISYNTH2, /*P3*/0, 1, /*P1*/0, 50, 0, /*P2|P3*/0, 0, 0,
2, SI5351_REG_18_CLK2_CONTROL, SI5351_CLK_DRIVE_STRENGTH_2MA | SI5351_CLK_INPUT_MULTISYNTH_N | SI5351_CLK_INTEGER_MODE,
2, SI5351_REG_3_OUTPUT_ENABLE_CONTROL, 0,
0 // sentinel
};
void
si5351_init(void)
{
const uint8_t *p = si5351_configs;
while (*p) {
uint8_t len = *p++;
si5351_bulk_write(p, len);
p += len;
}
}
void si5351_disable_output(void)
{
uint8_t reg[4];
si5351_write(SI5351_REG_3_OUTPUT_ENABLE_CONTROL, 0xff);
reg[0] = SI5351_REG_16_CLK0_CONTROL;
reg[1] = SI5351_CLK_POWERDOWN;
reg[2] = SI5351_CLK_POWERDOWN;
reg[3] = SI5351_CLK_POWERDOWN;
si5351_bulk_write(reg, 4);
}
void si5351_enable_output(void)
{
si5351_write(SI5351_REG_3_OUTPUT_ENABLE_CONTROL, 0x00);
}
void si5351_reset_pll(void)
{
//si5351_write(SI5351_REG_177_PLL_RESET, SI5351_PLL_RESET_A | SI5351_PLL_RESET_B);
si5351_write(SI5351_REG_177_PLL_RESET, 0xAC);
}
void si5351_setupPLL(uint8_t pll, /* SI5351_PLL_A or SI5351_PLL_B */
uint8_t mult,
uint32_t num,
uint32_t denom)
{
/* Get the appropriate starting point for the PLL registers */
const uint8_t pllreg_base[] = {
SI5351_REG_26_PLL_A,
SI5351_REG_34_PLL_B
};
uint32_t P1;
uint32_t P2;
uint32_t P3;
/* Feedback Multisynth Divider Equation
* where: a = mult, b = num and c = denom
* P1 register is an 18-bit value using following formula:
* P1[17:0] = 128 * mult + floor(128*(num/denom)) - 512
* P2 register is a 20-bit value using the following formula:
* P2[19:0] = 128 * num - denom * floor(128*(num/denom))
* P3 register is a 20-bit value using the following formula:
* P3[19:0] = denom
*/
/* Set the main PLL config registers */
if (num == 0)
{
/* Integer mode */
P1 = 128 * mult - 512;
P2 = 0;
P3 = 1;
}
else
{
/* Fractional mode */
//P1 = (uint32_t)(128 * mult + floor(128 * ((float)num/(float)denom)) - 512);
P1 = 128 * mult + ((128 * num) / denom) - 512;
//P2 = (uint32_t)(128 * num - denom * floor(128 * ((float)num/(float)denom)));
P2 = 128 * num - denom * ((128 * num) / denom);
P3 = denom;
}
/* The datasheet is a nightmare of typos and inconsistencies here! */
uint8_t reg[9];
reg[0] = pllreg_base[pll];
reg[1] = (P3 & 0x0000FF00) >> 8;
reg[2] = (P3 & 0x000000FF);
reg[3] = (P1 & 0x00030000) >> 16;
reg[4] = (P1 & 0x0000FF00) >> 8;
reg[5] = (P1 & 0x000000FF);
reg[6] = ((P3 & 0x000F0000) >> 12) | ((P2 & 0x000F0000) >> 16);
reg[7] = (P2 & 0x0000FF00) >> 8;
reg[8] = (P2 & 0x000000FF);
si5351_bulk_write(reg, 9);
}
void
si5351_setupMultisynth(uint8_t output,
uint8_t pllSource,
uint32_t div, // 4,6,8, 8+ ~ 900
uint32_t num,
uint32_t denom,
uint32_t rdiv, // SI5351_R_DIV_1~128
uint8_t drive_strength)
{
/* Get the appropriate starting point for the PLL registers */
const uint8_t msreg_base[] = {
SI5351_REG_42_MULTISYNTH0,
SI5351_REG_50_MULTISYNTH1,
SI5351_REG_58_MULTISYNTH2,
};
const uint8_t clkctrl[] = {
SI5351_REG_16_CLK0_CONTROL,
SI5351_REG_17_CLK1_CONTROL,
SI5351_REG_18_CLK2_CONTROL
};
uint8_t dat;
uint32_t P1;
uint32_t P2;
uint32_t P3;
uint32_t div4 = 0;
/* Output Multisynth Divider Equations
* where: a = div, b = num and c = denom
* P1 register is an 18-bit value using following formula:
* P1[17:0] = 128 * a + floor(128*(b/c)) - 512
* P2 register is a 20-bit value using the following formula:
* P2[19:0] = 128 * b - c * floor(128*(b/c))
* P3 register is a 20-bit value using the following formula:
* P3[19:0] = c
*/
/* Set the main PLL config registers */
if (div == 4) {
div4 = SI5351_DIVBY4;
P1 = P2 = 0;
P3 = 1;
} else if (num == 0) {
/* Integer mode */
P1 = 128 * div - 512;
P2 = 0;
P3 = 1;
} else {
/* Fractional mode */
P1 = 128 * div + ((128 * num) / denom) - 512;
P2 = 128 * num - denom * ((128 * num) / denom);
P3 = denom;
}
/* Set the MSx config registers */
uint8_t reg[9];
reg[0] = msreg_base[output];
reg[1] = (P3 & 0x0000FF00) >> 8;
reg[2] = (P3 & 0x000000FF);
reg[3] = ((P1 & 0x00030000) >> 16) | div4 | rdiv;
reg[4] = (P1 & 0x0000FF00) >> 8;
reg[5] = (P1 & 0x000000FF);
reg[6] = ((P3 & 0x000F0000) >> 12) | ((P2 & 0x000F0000) >> 16);
reg[7] = (P2 & 0x0000FF00) >> 8;
reg[8] = (P2 & 0x000000FF);
si5351_bulk_write(reg, 9);
/* Configure the clk control and enable the output */
dat = drive_strength | SI5351_CLK_INPUT_MULTISYNTH_N;
if (pllSource == SI5351_PLL_B)
dat |= SI5351_CLK_PLL_SELECT_B;
if (num == 0)
dat |= SI5351_CLK_INTEGER_MODE;
si5351_write(clkctrl[output], dat);
}
static uint32_t
gcd(uint32_t x, uint32_t y)
{
uint32_t z;
while (y != 0) {
z = x % y;
x = y;
y = z;
}
return x;
}
#define XTALFREQ 26000000L
#define PLL_N 32
#define PLLFREQ (XTALFREQ * PLL_N)
void
si5351_set_frequency_fixedpll(int channel, int pll, int pllfreq, int freq,
uint32_t rdiv, uint8_t drive_strength)
{
int32_t div = pllfreq / freq; // range: 8 ~ 1800
int32_t num = pllfreq - freq * div;
int32_t denom = freq;
//int32_t k = freq / (1<<20) + 1;
int32_t k = gcd(num, denom);
num /= k;
denom /= k;
while (denom >= (1<<20)) {
num >>= 1;
denom >>= 1;
}
si5351_setupMultisynth(channel, pll, div, num, denom, rdiv, drive_strength);
}
void
si5351_set_frequency_fixeddiv(int channel, int pll, int freq, int div,
uint8_t drive_strength)
{
int32_t pllfreq = freq * div;
int32_t multi = pllfreq / XTALFREQ;
int32_t num = pllfreq - multi * XTALFREQ;
int32_t denom = XTALFREQ;
int32_t k = gcd(num, denom);
num /= k;
denom /= k;
while (denom >= (1<<20)) {
num >>= 1;
denom >>= 1;
}
si5351_setupPLL(pll, multi, num, denom);
si5351_setupMultisynth(channel, pll, div, 0, 1, SI5351_R_DIV_1, drive_strength);
}
/*
* 1~100MHz fixed PLL 900MHz, fractional divider
* 100~150MHz fractional PLL 600-900MHz, fixed divider 6
* 150~200MHz fractional PLL 600-900MHz, fixed divider 4
*/
void
si5351_set_frequency(int channel, int freq, uint8_t drive_strength)
{
if (freq <= 100000000) {
si5351_setupPLL(SI5351_PLL_B, 32, 0, 1);
si5351_set_frequency_fixedpll(channel, SI5351_PLL_B, PLLFREQ, freq, SI5351_R_DIV_1, drive_strength);
} else if (freq < 150000000) {
si5351_set_frequency_fixeddiv(channel, SI5351_PLL_B, freq, 6, drive_strength);
} else {
si5351_set_frequency_fixeddiv(channel, SI5351_PLL_B, freq, 4, drive_strength);
}
}
int current_band = -1;
/*
* configure output as follows:
* CLK0: frequency + offset
* CLK1: frequency
* CLK2: fixed 8MHz
*/
#define CLK2_FREQUENCY 8000000L
int
si5351_set_frequency_with_offset(int freq, int offset, uint8_t drive_strength)
{
int band;
int delay = 5;
uint32_t ofreq = freq + offset;
uint32_t rdiv = SI5351_R_DIV_1;
if (freq > 300000000) {
freq /= 3;
ofreq /= 5;
}
if (freq <= 100000000) {
band = 0;
} else if (freq < 150000000) {
band = 1;
} else {
band = 2;
}
if (freq <= 500000) {
rdiv = SI5351_R_DIV_64;
} else if (freq <= 4000000) {
rdiv = SI5351_R_DIV_8;
}
#if 1
if (current_band != band)
si5351_disable_output();
#endif
switch (band) {
case 0:
// fractional divider mode. only PLL A is used.
if (current_band == 1 || current_band == 2)
si5351_setupPLL(SI5351_PLL_A, 32, 0, 1);
// Set PLL twice on changing from band 2
if (current_band == 2)
si5351_setupPLL(SI5351_PLL_A, 32, 0, 1);
if (rdiv == SI5351_R_DIV_8) {
freq *= 8;
ofreq *= 8;
} else if (rdiv == SI5351_R_DIV_64) {
freq *= 64;
ofreq *= 64;
}
si5351_set_frequency_fixedpll(0, SI5351_PLL_A, PLLFREQ, ofreq,
rdiv, SI5351_CLK_DRIVE_STRENGTH_2MA);
si5351_set_frequency_fixedpll(1, SI5351_PLL_A, PLLFREQ, freq,
rdiv, drive_strength);
//if (current_band != 0)
si5351_set_frequency_fixedpll(2, SI5351_PLL_A, PLLFREQ, CLK2_FREQUENCY,
SI5351_R_DIV_1, SI5351_CLK_DRIVE_STRENGTH_2MA);
break;
case 1:
// Set PLL twice on changing from band 2
if (current_band == 2) {
si5351_set_frequency_fixeddiv(0, SI5351_PLL_A, ofreq, 6,
SI5351_CLK_DRIVE_STRENGTH_2MA);
si5351_set_frequency_fixeddiv(1, SI5351_PLL_B, freq, 6, drive_strength);
}
// div by 6 mode. both PLL A and B are dedicated for CLK0, CLK1
si5351_set_frequency_fixeddiv(0, SI5351_PLL_A, ofreq, 6,
SI5351_CLK_DRIVE_STRENGTH_2MA);
si5351_set_frequency_fixeddiv(1, SI5351_PLL_B, freq, 6, drive_strength);
si5351_set_frequency_fixedpll(2, SI5351_PLL_B, freq * 6, CLK2_FREQUENCY,
SI5351_R_DIV_1, SI5351_CLK_DRIVE_STRENGTH_2MA);
break;
case 2:
// div by 4 mode. both PLL A and B are dedicated for CLK0, CLK1
si5351_set_frequency_fixeddiv(1, SI5351_PLL_B, freq, 4, drive_strength);
si5351_set_frequency_fixedpll(2, SI5351_PLL_B, freq * 4, CLK2_FREQUENCY,
SI5351_R_DIV_1, SI5351_CLK_DRIVE_STRENGTH_2MA);
si5351_set_frequency_fixeddiv(0, SI5351_PLL_A, ofreq, 4,
SI5351_CLK_DRIVE_STRENGTH_2MA);
break;
}
if (current_band != band) {
si5351_reset_pll();
#if 1
si5351_enable_output();
#endif
delay += 0;
}
current_band = band;
return delay;
}