I2C_State_Check return value meaning

[bludin]

Can you please tell me how to interpret the values that I2C_State_Check() return? Thanks in advance, Beat

[nonNoise]

I2C_State_Check() is Read a 0x10 Register. Please see the data sheet.

http://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf

Please look at page 23.

3.1 USB HID Commands/Responses 3.1.1 STATUS/SET PARAMETERS .... .... ....

This is the content of I2C_State_Check.

[bludin]

Yes, it is byte[8] of the Response 1 Structure, described as the Internal I2C state machine state value. But what do the various values (responses I see are 37, 69, 98, etc.) actually mean?

[nonNoise]

Aaaaa..... I remember !! When writing this source, I was troubled because I didn't understand the contents of the register in the same way.

I wrote it because the Microchip Linux driver is in C language.

http://ww1.microchip.com/downloads/en/DeviceDoc/mcp2221_0_1.tar.gz

The driver has the following declaration statement.

i2c-mcp2221.c

define RESP_I2C_IDLE 0x00

define RESP_I2C_START_TOUT 0x12

define RESP_I2C_RSTART_TOUT 0x17

define RESP_I2C_WRADDRL_TOUT 0x23

define RESP_I2C_WRADDRL_WSEND 0x21

define RESP_I2C_WRADDRL_NACK 0x25

define RESP_I2C_WRDATA_TOUT 0x44

define RESP_I2C_RDDATA_TOUT 0x52

define RESP_I2C_STOP_TOUT 0x62

---

Is it right? I didn't use it as a source because I didn't know it was correct.

(responses I see are 37, 69, 98, etc.)

37 = 0x25 = RESP_I2C_WRADDRL_NACK ? 69 = 0x45 = ??? 98 = 0x62 = RESP_I2C_STOP_TOUT ?

Can someone test it? If it matches, an error character is displayed. Thanks.

[bludin]

Thanks, that's quite helpful already. I cannot verify this, but I can possibly shed some light on the meaning of 37/0x25 and 69/0x45: 0x25 is the value immediately after the first I2C_Write_No_Stop, before performing a subsequent I2C_Read_Repeated (after which the state is 0x00 again. For all subsequent operations of this kind, I get 0x45 instead of 0x25.

[nonNoise]

Wow!! When I happened to look at the source of MCP2221A for Android, more detailed status was written.

69 = 0x45 = I2CM_SM_WRITEDATA_END_NOSTOP