I2C Control Registers
1399
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Inter-Integrated Circuit (I2C) Module
27.6.11 I2C Interrupt Vector Register (I2CIVR)
The I2C interrupt vector register is a 16-bit memory-mapped register used to indicate the occurrence of an
interrupt.
and
describe this register.
Figure 27-24. I2C Interrupt Vector Register (I2CIVR) [offset = 28h]
15
12
11
8
7
3
2
0
Reserved
TESTMD
Reserved
INTCODE
R-0
R/W-0
R-0
R/WC-0
LEGEND: R/W = Read/Write; R = Read only; C = Clear; -
n
= value after reset
Table 27-19. I2C Interrupt Vector Register (I2CIVR) Field Descriptions
Bit
Field
Value
Description
15-12
Reserved
0
Reads return 0. Writes have no effect.
11-8
TESTMD
0-3h
Reserved for internal testing.
7-3
Reserved
0
Reads return 0. Writes have no effect.
2-0
INTCODE
0-3h
Interrupt Code Bits
This binary coded interrupt vector indicates which interrupt has occurred. If there is more than
one interrupt pending, reading I2CIVR provides the vector for the highest-priority interrupt that is
pending.
Reading the I2CIVR will clear the corresponding flags in I2CSTR for AL, NACK and SCD as
long as those interrupts are enabled. A new interrupt will be generated for each pending source.
Reading I2CIVR will clear the INTCODE for AL, NACK, SCD, AAS, RXRDY and TXRDY.
Reading I2CIVR
will not
clear the INTCODE for ARDY.
The INTCODE for certain codes can also be cleared by either writing a 1 to the corresponding
interrupt flag bits in I2CSTR, or by reading and writing to the receive or transmit registers. See
for more details.
Users must read (clear) the I2CIVR before doing another start otherwise the I2CIVR could
contain incorrect (old interrupt flag) value.
Table 27-20. Interrupt Codes for INTCODE Bits
Code
INTCODE(2-0)
Interrupt Occurred
00h
000
none
01h
001 (highest priority)
Arbitration lost (AL)
02h
010
No acknowledgement (NACK)
03h
011
Register access ready (ARDY)
04h
100
Receive data ready (RXRDY)
05h
101
Transmit data ready (TXRDY)
06h
110
Stop condition detect (SCD)
07h
111 (lowest priority)
Address as slave (AAS)