lpc55xx_hic: Add documentation for MCU-LINK and MCU-LINK-PRO support
@@ -31,17 +31,60 @@ Reference design is based on [MCU-Link](https://www.nxp.com/design/development-b
| SWDIO / TMS | I/O | PIO0_2 | 52 |
| SWO / TDO | I | PIO0_3 | 53 |
| TDI | O | PIO0_1 | 2 |
-| nRESET | O | PIO0_19 | 58 |
+| nRESET | I/O | PIO0_19 | 58 |
| GNDDetect | I | PIO0_22 | 50 |
| UART |
| UART RX | I | PIO0_24 | 45 |
| UART TX | O | PIO0_25 | 51 |
-| Button |
-| NF-RST But. | I | PIO0_18 | 38 |
-| F-RST But. | I | PIO1_27 | 18 |
| LEDs |
| Con. LED | O | PIO0_5 | 56 |
Additional pins are used to drive external circuitry:
- SWDIO TX Enable (PIO0_28, pin 44)
- nRESET Output Enable (PIO0_13, pin 46)
+
+## MCU-LINK and MCU-LINK-PRO support
+
+The `lpc55s69_mculink_bl` and `lpc55s69_mculink_if` images support both
+MCU-LINK and MCU-LINK-PRO boards. Installation of the bootloader can be
+done by putting the board in firmware update mode and using the NXP
+`blhost` tool:
+
+```
+$ blhost --usb 0x1fc9,0x0021 flash-image lpc55s69_mculink_bl_crc.hex erase
+```
+
+### MCU-LINK "Buttoms"
+
+The MCU-LINK does not have amy buttons, but both board have "Disable VCOM"
+and "Disable SWD" respectively mapped to non-forwarding reset and
+forwarding reset functionality in DAPLink.
+
+| Signal | I/O | Symbol | Pin |
+|-------------|:---:|---------|:---:|
+| Button |
+| NF-RST But. | I | PIO0_18 | 38 |
+| F-RST But. | I | PIO0_27 | 18 |
+
+### MCU-LINK-PRO detection and LEDs
+
+The [MCU-LINK-PRO](https://www.nxp.com/design/microcontrollers-developer-resources/mcu-link-pro-debug-probe:MCU-LINK-PRO)
+defines board type detection using `HW_VER_4` and `HW_VER_3`. When
+`HW_VER_4` and `HW_VER_3` are respectively low and high, we determine that
+the board is a MCU-LINK-PRO, otherwise we assume the board is a MCU-LINK.
+MCU-LINK only has one red activity LED. MCU-LINK-PRO has 7 LEDs (1 red
+and 6 green), 5 are currently used by DAPLink (see table below).
+
+| Signal | I/O | Symbol |
+|---------------|:---:|---------|
+| Detection |
+| HW_VER_4 | I | PIO1_5 |
+| HW_VER_3 | I | PIO1_4 |
+| LEDs |
+| Con. LED (r) | O | PIO0_5 |
+| Run. LED (g) | O | PIO1_17 |
+| HID LED (g) | O | PIO1_13 |
+| CDC LED (g) | O | PIO1_18 |
+| MSC LED (g) | O | PIO1_15 |
+| N/A LED 1 (g) | O | PIO1_12 |
+| N/A LED 2 (g) | O | PIO1_12 |
