I2C Controller
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
39-6 Freescale Semiconductor
39.4 I2C Registers

The following sections describe the I2C registers.

39.4.1 I2C Mode Register (I2MOD)

The I2C mode register, shown in Figure39-6, controls the I2C modes and clock source.

Table39-1 describes I2MOD bit functions.

39.4.2 I2C Address Register (I2ADD)

The I2C address register, shown in Figure 39-7, holds the address for this I2C port.

01234567
Field REVD GCD FLT PDIV EN
Reset 0000_0000
R/W R/W
Addr 0x0x11860
Figure 39-6. I2C Mode Register (I2MOD)
Table39-1. II2MOD Field Descri ptions
Bits Name Description
0–1 Reserved and should be cleared.
2 REVD Reverse data. Determines the Rx and Tx character bit order.
0 Normal operation. The msb (bit 0) of a character is transferred first.
1 Reverse data. the lsb (bit 7) of a character is transferred first.
Note:Clearing REVD is strongly recommended to ensure consistent bit ordering across devices.
3 GCD General call disable. Determines whether the receiver acknowledges a general call address.
0 General call address is enabled.
1 General call address is disabled.
4 FLT Clock filter. Determines if the I2C input clock SCL is filtered to prevent spikes in a noisy environment.
0 SCL is not filtered.
1 SCL is filtered by a digital filter.
5–6 PDIV Predivider. Selects the clock division factor before it is input into the I2C BRG. The clock source for
the I2C BRG is the BRGCLK generated from the CPM clock; see Section10.8, “System Clock
Control Register (SCCR).”
00 BRGCLK/32
01 BRGCLK/16
10 BRGCLK/8
11 BRGCLK/4
Note:To both save power and reduce noise susceptibility, select the PDIV with the largest division
factor (slowest clock) that still meets performance requirements.
7 EN Enable I2C operation.
0I
2C is disabled. The I2C is in a reset state and consumes minimal power.
1I
2C is enabled. Do not change other I2MOD bits when EN is set.