uVision2

Manoel_Filho · Joined: 15 Mar 2015 Posts: 3

Hi there.

Does any good soul can translate this code to me?

jeremiah · Joined: 20 Jul 2010 Posts: 1346

if you are gonna work with CCS, you are better off not trying to port the uVision code directly. Think of the I2C functionality in terms of actions: initializing, reading the port, writing the port, start/stop for communication.

Then look at the compiler manual (or help if in the IDE) for:
#USE I2C
i2c_start
i2c_stop
i2c_write
i2c_read

Manoel_Filho · Joined: 15 Mar 2015 Posts: 3

Ok Jeremiah. Thank you! I know the I2C procedures, no issue about this. The main problem is that this device BK-1080, is a little bit weird. The device ID have 16 bits with ACK. The initial address bit is also 16 bits with ACK afte the 16th bit, but for the rest, you can split the registers in 2x8bits with an ACK between them. Thats why I was trying to understand what the manufactor did on this software. So if you or any one else can help me I appreciate that.

Regards

Ttelmah · Joined: 11 Mar 2010 Posts: 19506

The code means nothing, without knowing the chip it is used on, and how the hardware is wired.
However some parts can be worked out:

#define BK_DATA_HIGH() P02=1;

Sets something called P02 to 1.
Possibly Port 0, bit 2?.

The next line is the same to set the same thing low.

Then:

#define SDADIROUT() P0DIR &= ~(1<<2);

Turns off bit 2, in the 'P0' direction register (equivalent to TRIS?)

Takes 1
Shifts it twice to give 00000100
Inverts this to give 11111011
&'s this with the direction register (so if this is TRIS, sets bit 2 to an output)

Then:

P0PU |= (1<<2)

Possible something like a port 0 'pull up' register?. Again would need to know the hardware. This sets bit 2 in this register.

Without knowing the chip involved though, these are all going to be guesses.

The CCS _software_ I2C implementation can do an ACK after bit 16. The PIC hardware can't.

However you are misreading the data sheet. The chip requires an ACK after every byte sent (standard I2C). It takes an 8bit device address (0x80), followed by a seven bit register address and the R/W bit. This is fractionally different from standard, where the device address is normally 7bits, with the R/W bit then added, but the standard I2C hardware will handle this OK.
Several of the registers are 16bit, but each is transferred a byte at a time.

Manoel_Filho · Joined: 15 Mar 2015 Posts: 3

You are completely right.

I can perfect communicate with the chip, no problem.

Thank you,

regards.