From 053c16b84e05274cfca2d3ba04bcab7fb32a88a2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ren=C3=A9=20van=20Dorst?= Date: Mon, 22 Dec 2025 14:32:23 +0100 Subject: [PATCH] SWTG024AS: Document Slave Interface --- doc/devices/SWTG024AS.md | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/doc/devices/SWTG024AS.md b/doc/devices/SWTG024AS.md index 4308e13..c893429 100644 --- a/doc/devices/SWTG024AS.md +++ b/doc/devices/SWTG024AS.md @@ -91,21 +91,28 @@ Note: component numbering `--` * SIDE: Side of the component. when the rj45 are facing towards you are you can read the silkscreen normal. L = Left, R=right, B=bottom, T=top or P with a pin number. -### T3 -This connector seems to go to U4 and U10. -I thing is used to connect a external CPU to controlle the SOC. -Even to program the flash via the SOC. +### T3, Slave Interface +This connector goes to U4 `I2C EEPROM` and U10 `SPI FLASH`. Signals are based on that `U4` is likely a I2C-EEPROM, `U10` is likely other SPI-chip. |`T3` pin|what|Signal| |---|---|---| -|1| U4-P6, 33R U10-P6 | I2C-SCL, SPI-CLK | +|1| U4-P6, 33R U10-P6 | I2C-SCL, SPI-CLK, Slave SCK/SCL/MDC/EE_SCL | |2| GND | --- | -|3| U4-P5, U10-P5 | I2C-SDA, SPI-DI/DO | +|3| U4-P5, U10-P5 | I2C-SDA, SPI-DI/DO, Slave SDI/SDA/MDIO/EE_SDA | |4| VCC | |5| 33R -> U10-P2 | SPI-DO/D1 | |6| U10-P1 | SPI-CS | Note: 1 pin is square shaped. +The Slave Interface allows an extenal host to controll the SOC even if the internal MCU is used. +Depending on the `IF_SEL` bootstrap resistors, this can me `I2C`, `SPI` or `SMI`. +On this device it is `I2C` on address `0b1011100` or `0x5c` (7-bit notation). + +* I2c Read: must be a write_read opperation `` ``. +* I2c Write: ``. + +Example register `0x0004` return chip id `0x00, 0x00, 0x72, 0x83` = `0x83720000`. + ### T5, serial console |`T5` pin|GPIO|Signal| |---|---|---|