I2C Controller
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 39-7

Table39-2 describes I 2ADD fields.

39.4.3 I2C Baud Rate Generator Register (I2BRG)

The I2C baud rate generator register, shown in Figure 39-8, sets the divide ratio of the I2C BRG.

Table39-3 describes I2BRG fields.

39.4.4 I2C Event/Mask Registers (I2CER/I2CMR)

The I2C event register (I2CER) is used to generate interrupts and report events. When an event is

recognized, the I2C controller sets the corresponding I2CER bit. I2CER bits are cleared by writing ones;

writing zeros has no effect. Setting a bit in the I2C mask register (I2CMR) enables and clearing a bit masks

the corresponding interrupt. Unmasked I2CER bits must be cleared before the CP clears internal interrupt

requests. Figure 39-9 shows both registers.

067
Field SAD
Reset Undefined
R/W R/W
Addr 0x0x11864

Figure 39-7. I2C Address Register (I2ADD)

Table39-2. I2ADD Field Descr iptions

Bits Name Description
0–6 SAD Slave address 0–6. Holds the slave address for the I2C port.
7 Reserved and should be cleared.
0 7
Field DIV
Reset 1111_1111
R/W R/W
Addr 0x0x11868

Figure 39-8. I2C Baud Rate Generator Register (I2BRG)

Table39-3. I2BRG F ield Descriptions

Bits Name Description
0–7 DIV Division ratio 0–7. Specifies the divide ratio of the BRG divider in the I2C clock generator. The output
of the prescaler is divided by 2 * ([DIV0–DIV7] + 3 + (2 * I2MOD[FLT])) and the clock has a 50% duty
cycle. DIV must be programmed to a minimum value of 3 if the digital filter is disabled
(I2MOD[FLT]= 0) and 6 if it is enabled (I2MOD[FLT]= 1) .