1.6.6 External Interrupt Control Registers
Three external interrupts, XINT1–XINT3, are supported. Each of these external interrupts can be selected for
negative or positive edge triggered and can also be enabled or disabled. The masked interrupts also contain a
16-bit free-running up-counter that is reset to zero when a valid interrupt edge is detected. This counter can be
used to accurately time stamp the interrupt.
Table 1-129. Interrupt Control and Counter Registers (not EALLOW Protected)
Name
Address Range
Size (x16)
Description
XINT1CR
0x0000 7070
1
XINT1 configuration register
XINT2CR
0x0000 7071
1
XINT2 configuration register
XINT3CR
0x0000 7072
1
XINT3 configuration register
reserved
0x0000 7073 - 0x0000 7077
5
XINT1CTR
0x0000 7078
1
XINT1 counter register
XINT2CTR
0x0000 7079
1
XINT2 counter register
XINT3CTR
0x0000 707A
1
XINT3 counter register
reserved
0x0000 707B - 0x0000 707E
5
XINT1CR through XINT3CR are identical except for the interrupt number; therefore,
represent registers for external interrupts 1 through 3 as XINT
n
CR where
n
= the interrupt number.
Figure 1-105. External Interrupt n Control Register (XINTnCR)
15
4
3
2
1
0
Reserved
Polarity
Reserved
Enable
R-0
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 1-130. External Interrupt n Control Register (XINTnCR) Field Descriptions
Bits
Field
Value
Description
15-4
Reserved
Reads return zero; writes have no effect.
3-2
Polarity
This read/write bit determines whether interrupts are generated on the rising edge or the
falling edge of a signal on the pin.
00
Interrupt generated on a falling edge (high-to-low transition)
01
Interrupt generated on a rising edge (low-to-high transition)
10
Interrupt generated on a falling edge (high-to-low transition)
11
Interrupt generated on both a falling edge and a rising edge (high-to-low and low-to-high
transition)
1
Reserved
Reads return zero; writes have no effect
0
Enable
This read/write bit enables or disables external interrupt XINT
n.
0
Disable interrupt
1
Enable interrupt
For XINT1, XINT2, and XINT3, there is also a 16-bit counter that is reset to 0x000 whenever an interrupt edge
is detected. These counters can be used to accurately time stamp an occurrence of the interrupt. XINT1CTR
through XINT3CTR are identical except for the interrupt number; therefore,
and
represent registers for the external interrupts as XINTnCTR, where n = the interrupt number.
System Control and Interrupts
192
TMS320x2806x Microcontrollers
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
Copyright © 2022 Texas Instruments Incorporated
Summary of Contents for TMS320 2806 Series
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