On Fri, Apr 16, 2004 at 11:01:49PM +0200, Jean Delvare wrote: > > In recent discussion about IBM IIC I mentioned that I had a hw were > > 1-byte read scan locked the bus. > > > > I just rechecked IBM PPC 440GP ref platform "Ebony" and indeed it has > > an i2c device which behaves this way. > > > > According to Ebony manual it's a CDC850 clock buffer (i2c address > > 0x69). To recover the i2c bus I have to reset the whole board, not > > just I2C controller. > > With "1-byte read" do you refer to SMBus' "quick command" with bit 1: > S Addr 1 [A] P > or "receive byte"? > S Addr Rd [A] [Data] NA P Receive byte of course (your second example), if you remember "quick command" isn't implemented for IBM PPC 4xx IIC controller ... yet. Eugene.
