Configuration¶
JP150PCB 1.3PCB 1.4Jan PřibyslavskýThis page does not apply to the product or PCB revision chosen in the header.
Three things are configured on the board itself: the DSP boot source, the MCU boot mode and the output bridging. PCB 1.3 uses a DIP switch for the first two; PCB 1.4 has no DIP switch and keeps them in firmware settings and a factory jumper.
DSP boot and MCU boot¶
PCB 1.4 has no configuration DIP switch. since 26.10.1
| Function | Where it lives on PCB 1.4 |
|---|---|
| DSP self boot from the boot memory | A stored firmware setting, on by default. MuraLink shows it on DSP > Status (Self boot), read-only, because switching it off stops the audio until the next start; it is changed over the control interface, DSP:SELFBOOT with 1 or 0, and acts at the next DSP reset, so a power cycle follows a change. |
| Master clock source | Selected by the firmware. The current firmware always selects the internal clock. |
| MCU boot mode | The ST ROM bootloader is reachable only through a factory solder jumper (STM BOOT) and is unavailable on production modules. Firmware updates and recovery go through the module's own update mode: Firmware updates. |
A three-position DIP switch next to the DSP.
| Switch | Function | ON | OFF |
|---|---|---|---|
| 1 | DSP EEPROM BOOT | The DSP loads its program from the on-board EEPROM at power-up | Disabled: for development over the DSP I2C connector |
| 2 | INTERNAL MCLK | Internal master clock | No effect in the current firmware: the module always runs from its internal clock |
| 3 | MCU BOOT MODE | ST ROM bootloader | Normal operation |
Switch 3 from firmware 26.10.1
A PCB 1.3 module that runs firmware 26.10.1 or later must keep switch 3 OFF for good. The old updater cannot talk to such a module, and a wrong move can erase it. Updates come through MuraLink: Update with MuraLink.
The firmware also stores a DSP self-boot setting (DSP:SELFBOOT); a closed switch 1 wins over it.
Output bridging (BTL and PBTL)¶
Each TAS3251 drives two channels in BTL, or one channel in PBTL with double the current. The bridging is set with three solder jumpers per power stage (silkscreen: BTL = open, PBTL = closed, all three alike), on both revisions. The DSP program must match: a PBTL stage expects one channel.
Reset button¶
The push button marked STM RST resets the host MCU and its peripherals. Settings are kept; the module starts as after a power cycle.