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-rw-r--r--ports/samd/Makefile3
-rw-r--r--ports/samd/machine_bitstream.c206
-rw-r--r--ports/samd/modmachine.c2
-rw-r--r--ports/samd/mpconfigport.h1
-rw-r--r--ports/samd/mphalport.h4
-rw-r--r--ports/samd/samd_soc.c2
6 files changed, 214 insertions, 4 deletions
diff --git a/ports/samd/Makefile b/ports/samd/Makefile
index 1455e748c..f1bc67e6e 100644
--- a/ports/samd/Makefile
+++ b/ports/samd/Makefile
@@ -87,10 +87,11 @@ LIBSTDCPP_FILE_NAME = "$(shell $(CXX) $(CXXFLAGS) -print-file-name=libstdc++.a)"
LDFLAGS += -L"$(shell dirname $(LIBSTDCPP_FILE_NAME))"
endif
-SRC_C = \
+SRC_C += \
clock_config.c \
help.c \
machine_adc.c \
+ machine_bitstream.c \
machine_dac.c \
machine_i2c.c \
machine_led.c \
diff --git a/ports/samd/machine_bitstream.c b/ports/samd/machine_bitstream.c
new file mode 100644
index 000000000..9959d947c
--- /dev/null
+++ b/ports/samd/machine_bitstream.c
@@ -0,0 +1,206 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Jim Mussared
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+// This is a translation of the cycle counter implementation in ports/stm32/machine_bitstream.c.
+
+#include "py/mpconfig.h"
+#include "py/mphal.h"
+#include "clock_config.h"
+
+#if MICROPY_PY_MACHINE_BITSTREAM
+
+#if __CORTEX_M == 0
+
+// No cycle counter on M0, do manual cycle counting instead.
+
+// STM32F091 @ 48MHz
+#define NS_CYCLES_PER_ITER_HIGH (3)
+#define NS_CYCLES_PER_ITER_LOW (3)
+#define NS_OVERHEAD_CYCLES_HIGH (12)
+#define NS_OVERHEAD_CYCLES_LOW (15)
+
+uint32_t mp_hal_delay_ns_calc(uint32_t ns, bool high) {
+ uint32_t ncycles = (get_cpu_freq() / 1000000 * ns + 500) / 1000; // + 500 for proper rounding
+ uint32_t overhead = MIN(ncycles, high ? NS_OVERHEAD_CYCLES_HIGH : NS_OVERHEAD_CYCLES_LOW);
+ return MAX(1, MP_ROUND_DIVIDE(ncycles - overhead, high ? NS_CYCLES_PER_ITER_HIGH : NS_CYCLES_PER_ITER_LOW));
+}
+
+void machine_bitstream_high_low(mp_hal_pin_obj_t pin, uint32_t *timing_ns, const uint8_t *buf, size_t len) {
+ volatile const uint32_t mask = 1 << (pin % 32);
+ volatile uint32_t *outclr = &PORT->Group[pin / 32].OUTCLR.reg;
+ volatile uint32_t *outset = &PORT->Group[pin / 32].OUTSET.reg;
+
+ // Convert ns to loop iterations [high_time_0, low_time_0, high_time_1, low_time_1].
+ for (size_t i = 0; i < 4; ++i) {
+ timing_ns[i] = mp_hal_delay_ns_calc(timing_ns[i], i % 2 == 0);
+ }
+
+ mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
+
+ // Measured timing for SAMD21 at 48MHz (cycle=20.83ns)
+ // timing_ns = (1,1,1,1)
+ // high: 310
+ // low: 375
+ // high0: 375
+ // low0: 400
+ // timing_ns = (500, 500, 500, 500)
+ // high: 500
+ // low: 500
+ // high0: 565
+ // low0: 540
+ // timing_ns = (1000, 1000, 1000, 1000)
+ // high: 1000
+ // low: 1000
+ // high0: 1065
+ // low0: 1040
+
+ // --> high is 12 + n*3 cycles
+ // low is 15 + n*3 cycles
+
+ // NeoPixel timing (400, 850, 800, 450) (+/-150ns) gives timing_ns=(2, 9, 8, 3) which in cycles is
+ // (12 + 6, 15 + 27, 15 + 24, 12 + 9) = (18, 42, 39, 21)
+ // --> (375, 875, 812, 437) nanoseconds.
+ // Measured output on logic analyser is (375, 875, 815, 435) (+/-5ns at 200MHz)
+
+ // Note: the first high/low cycle is longer by 2-3 cycles (40-60ns).
+ // This is slightly outside spec, but doesn't seem to cause a problem.
+
+ __asm volatile (
+ // Force consistent register assignment.
+ // r6 = len
+ "ldr r6, %0\n"
+ // r4 = buf
+ "ldr r4, %1\n"
+ // r5 = timing_ms
+ "ldr r5, %2\n"
+
+ // Must align for consistent timing.
+ ".align 4\n"
+
+ // Don't increment/decrement before first iteration.
+ "b .outer2\n"
+ ".outer:\n"
+ // ++buf, --len
+ " add r4, #1\n"
+ " sub r6, #1\n"
+
+ // len iterations
+ ".outer2:\n"
+ " cmp r6, #0\n"
+ " beq .done\n"
+
+ // r0 = *buf
+ " ldrb r0, [r4, #0]\n"
+
+ // 8 bits in byte
+ " mov r7, #8\n"
+ " .inner:\n"
+ // *outset = mask
+ " ldr r2, %3\n"
+ " ldr r1, %5\n"
+ " str r1, [r2, #0]\n"
+
+ // r3 = (r0 >> 4) & 8 (r0 is 8 if high bit is 1 else 0)
+ " mov r8, r6\n"
+ " lsr r3, r0, #4\n"
+ " mov r6, #8\n"
+ " and r3, r6\n"
+ " mov r6, r8\n"
+
+ // r2 = timing_ns[r2]
+ " ldr r2, [r5, r3]\n"
+ " .loop1:\n sub r2, #1\n bne .loop1\n"
+
+ // *outclr = mask
+ " ldr r2, %4\n"
+ " str r1, [r2, #0]\n"
+
+ // r2 = timing_ns[r3 + 4]
+ " add r3, #4\n"
+ " ldr r2, [r5, r3]\n"
+ " .loop2:\n sub r2, #1\n bne .loop2\n"
+
+ // b >>= 1
+ " lsl r0, r0, #1\n"
+
+ " sub r7, #1\n"
+ // end of inner loop
+ " beq .outer\n"
+ // continue inner loop
+ " b .inner\n"
+
+ ".done:\n"
+ :
+ : "m" (len), "m" (buf), "m" (timing_ns), "m" (outset), "m" (outclr), "m" (mask)
+ : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8"
+ );
+
+ MICROPY_END_ATOMIC_SECTION(atomic_state);
+}
+
+#else // > CORTEX_M0
+
+#define NS_TICKS_OVERHEAD (70)
+
+void machine_bitstream_high_low(mp_hal_pin_obj_t pin, uint32_t *timing_ns, const uint8_t *buf, size_t len) {
+ uint32_t fcpu_mhz = get_cpu_freq() / 1000000;
+ uint32_t ticks_overhead = fcpu_mhz * NS_TICKS_OVERHEAD / 1000;
+ // Convert ns to us ticks [high_time_0, period_0, high_time_1, period_1].
+ for (size_t i = 0; i < 4; ++i) {
+ timing_ns[i] = fcpu_mhz * timing_ns[i] / 1000;
+ if (timing_ns[i] > ticks_overhead) {
+ timing_ns[i] -= ticks_overhead;
+ }
+ if (i % 2 == 1) {
+ // Convert low_time to period (i.e. add high_time).
+ timing_ns[i] += timing_ns[i - 1] - ticks_overhead;
+ }
+ }
+
+ mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
+ DWT->CYCCNT = 0;
+
+ for (size_t i = 0; i < len; ++i) {
+ uint8_t b = buf[i];
+ for (size_t j = 0; j < 8; ++j) {
+ uint32_t start_ticks = mp_hal_ticks_cpu();
+ uint32_t *t = &timing_ns[b >> 6 & 2];
+ mp_hal_pin_high(pin);
+ while ((mp_hal_ticks_cpu() - start_ticks) < t[0]) {
+ }
+ b <<= 1;
+ mp_hal_pin_low(pin);
+ while ((mp_hal_ticks_cpu() - start_ticks) < t[1]) {
+ }
+ }
+ }
+ MICROPY_END_ATOMIC_SECTION(atomic_state);
+
+}
+
+#endif // > CORTEX_M0
+
+#endif // MICROPY_PY_MACHINE_BITSTREAM
diff --git a/ports/samd/modmachine.c b/ports/samd/modmachine.c
index c191afda7..f6cf7f815 100644
--- a/ports/samd/modmachine.c
+++ b/ports/samd/modmachine.c
@@ -25,6 +25,7 @@
*/
#include "py/runtime.h"
+#include "extmod/machine_bitstream.h"
#include "extmod/machine_mem.h"
#include "extmod/machine_pulse.h"
#include "extmod/machine_i2c.h"
@@ -167,6 +168,7 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR_disable_irq), MP_ROM_PTR(&machine_disable_irq_obj) },
{ MP_ROM_QSTR(MP_QSTR_enable_irq), MP_ROM_PTR(&machine_enable_irq_obj) },
{ MP_ROM_QSTR(MP_QSTR_time_pulse_us), MP_ROM_PTR(&machine_time_pulse_us_obj) },
+ { MP_ROM_QSTR(MP_QSTR_bitstream), MP_ROM_PTR(&machine_bitstream_obj) },
};
STATIC MP_DEFINE_CONST_DICT(machine_module_globals, machine_module_globals_table);
diff --git a/ports/samd/mpconfigport.h b/ports/samd/mpconfigport.h
index 8a067d348..986c42fc7 100644
--- a/ports/samd/mpconfigport.h
+++ b/ports/samd/mpconfigport.h
@@ -111,6 +111,7 @@
#define MICROPY_PY_MACHINE_SPI (1)
#define MICROPY_PY_MACHINE_SOFTSPI (1)
#define MICROPY_PY_OS_DUPTERM (3)
+#define MICROPY_PY_MACHINE_BITSTREAM (1)
#define MICROPY_PY_MACHINE_PULSE (1)
#define MICROPY_PY_MACHINE_PWM (1)
#define MICROPY_PY_MACHINE_PWM_INIT (0)
diff --git a/ports/samd/mphalport.h b/ports/samd/mphalport.h
index b7e65da35..f1efd5500 100644
--- a/ports/samd/mphalport.h
+++ b/ports/samd/mphalport.h
@@ -71,11 +71,11 @@ static inline mp_uint_t mp_hal_ticks_us(void) {
#endif
}
-#if defined (MCU_SAMD21)
+#if defined(MCU_SAMD21)
#define mp_hal_ticks_cpu mp_hal_ticks_us
-#elif defined (MCU_SAMD51)
+#elif defined(MCU_SAMD51)
static inline void mp_hal_ticks_cpu_enable(void) {
CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
DWT->CYCCNT = 0;
diff --git a/ports/samd/samd_soc.c b/ports/samd/samd_soc.c
index aca6df0dd..d0df4a7e2 100644
--- a/ports/samd/samd_soc.c
+++ b/ports/samd/samd_soc.c
@@ -111,7 +111,7 @@ void samd_init(void) {
SysTick_Config(get_cpu_freq() / 1000);
init_us_counter();
usb_init();
- #if defined (MCU_SAMD51)
+ #if defined(MCU_SAMD51)
mp_hal_ticks_cpu_enable();
#endif
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-11-13 06:59:54 +0000