Datasheet

Table Of Contents
Bits Name Description Type Reset
11 SPECIAL This bit indicates whether software performs a Device-ID or
General Call or START BYTE command. - 0: ignore bit 10
GC_OR_START and use IC_TAR normally - 1: perform
special I2C command as specified in Device_ID or
GC_OR_START bit Reset value: 0x0
0x0 -> Disables programming of GENERAL_CALL or
START_BYTE transmission
0x1 -> Enables programming of GENERAL_CALL or
START_BYTE transmission
RW 0x0
10 GC_OR_START If bit 11 (SPECIAL) is set to 1 and bit 13(Device-ID) is set to
0, then this bit indicates whether a General Call or START
byte command is to be performed by the DW_apb_i2c. - 0:
General Call Address - after issuing a General Call, only
writes may be performed. Attempting to issue a read
command results in setting bit 6 (TX_ABRT) of the
IC_RAW_INTR_STAT register. The DW_apb_i2c remains in
General Call mode until the SPECIAL bit value (bit 11) is
cleared. - 1: START BYTE Reset value: 0x0
0x0 -> GENERAL_CALL byte transmission
0x1 -> START byte transmission
RW 0x0
9:0 IC_TAR This is the target address for any master transaction. When
transmitting a General Call, these bits are ignored. To
generate a START BYTE, the CPU needs to write only once
into these bits.
If the IC_TAR and IC_SAR are the same, loopback exists but
the FIFOs are shared between master and slave, so full
loopback is not feasible. Only one direction loopback mode
is supported (simplex), not duplex. A master cannot
transmit to itself; it can transmit to only a slave.
RW 0x055
IC_SAR Register
Description
I2C Slave Address Register
RP2040 Datasheet
4.4. I2C 492