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stc15: fix baudrate switching

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Baudrate switching fixes for both HW and SW UART devices:

* Program secondary SW UART timing parameter correctly. Supposedly this
  controls the sampling position when receiving data.
* Swap around trim range/adjust parameter for HW UART devices (as
  determind by older traces)
* Use correct constant for timing calculations

This should fix some STC15x10xW series MCUs. Compatibility to other
devices might be improved as well.

Addresses #17.
This commit is contained in:
Grigori Goronzy 2021-01-06 19:18:23 +01:00
parent 77df068efd
commit df2fbc23cd
1 changed files with 8 additions and 5 deletions
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13
stcgal/protocols.py
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@ -1394,9 +1394,12 @@ class Stc15Protocol(Stc15AProtocol):
# hardware UART. Only one family of models seems to lack a hardware
# UART, and we can isolate those with a check on the magic.
# This is a bit of a hack, but it works.
bauds = self.baud_transfer if (self.mcu_magic >> 8) == 0xf2 else self.baud_transfer * 4
packet += struct.pack(">H", int(65535 - program_speed / bauds))
packet += bytes(user_trim)
if (self.mcu_magic >> 8) == 0xf2:
packet += struct.pack(">H", int(65536 - program_speed / self.baud_transfer))
packet += struct.pack(">H", int(65536 - program_speed / 2 * 3 / self.baud_transfer))
else:
packet += struct.pack(">H", int(65536 - program_speed / (self.baud_transfer * 4)))
packet += bytes(reversed(user_trim))
iap_wait = self.get_iap_delay(program_speed)
packet += bytes([iap_wait])
self.write_packet(packet)
@ -1413,7 +1416,7 @@ class Stc15Protocol(Stc15AProtocol):
sys.stdout.flush()
packet = bytes([0x01])
packet += bytes([self.freq_count_24, 0x40])
packet += struct.pack(">H", int(65535 - self.mcu_clock_hz / self.baud_transfer / 4))
packet += struct.pack(">H", int(65536 - self.mcu_clock_hz / self.baud_transfer / 4))
iap_wait = self.get_iap_delay(self.mcu_clock_hz)
packet += bytes([0x00, 0x00, iap_wait])
self.write_packet(packet)
@ -1664,7 +1667,7 @@ class Stc8Protocol(Stc15Protocol):
sys.stdout.flush()
packet = bytes([0x01, 0x00, 0x00])
bauds = self.baud_transfer * 4
packet += struct.pack(">H", round(65535 - 24E6 / bauds))
packet += struct.pack(">H", round(65536 - 24E6 / bauds))
packet += bytes([user_trim[1], user_trim[0]])
iap_wait = self.get_iap_delay(24E6)
packet += bytes([iap_wait])