RTI Control Registers
600
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Real-Time Interrupt (RTI) Module
17.3.5 RTI Free Running Counter 0 Register (RTIFRC0)
The free running counter 0 register holds the current value of free running counter 0. This register is
shown in
and described in
Figure 17-16. RTI Free Running Counter 0 Register (RTIFRC0) [offset = 10h]
31
16
FRC0
R/WP-0
15
0
FRC0
R/WP-0
LEGEND: R/W = Read/Write; WP = Write in privileged mode only; -
n
= value after reset
Table 17-6. RTI Free Running Counter 0 Register (RTIFRC0) Field Descriptions
Bit
Field
Value
Description
31-0
FRC0
0-FFFF FFFFh
Free running counter 0. This registers holds the current value of the free running counter 0.
A read of this counter returns the current value of the counter.
The counter can be preset by writing (in privileged mode only) to this register. The counter
increments then from this written value upwards.
Note: If counters must be preset, they must be disabled in the RTIGCTRL register to
ensure consistency between RTIUC0 and RTIFRC0.
17.3.6 RTI Up Counter 0 Register (RTIUC0)
The up counter 0 register holds the current value of prescale counter. This register is shown in
and described in
.
Figure 17-17. RTI Up Counter 0 Register (RTIUC0) [offset = 14h]
31
16
UC0
R/WP-0
15
0
UC0
R/WP-0
LLEGEND: R/W = Read/Write; WP = Write in privileged mode only; -
n
= value after reset
Table 17-7. RTI Up Counter 0 Register (RTIUC0) Field Descriptions
Bit
Field
Value
Description
31-0
UC0
0-FFFF FFFFh
Up counter 0. This register holds the current value of the up counter 0 and prescales the RTI
clock. It will be only updated by a previous read of free running counter 0 (RTIFRC0). This
method of updating effectively gives a 64-bit read of both counters, without having the problem
of a counter being updated between two consecutive reads on up counter 0 (RTIUC0) and free
running counter 0 (RTIFRC0).
A read of this counter returns the value of the counter at the time RTIFRC0 was read.
A write to this counter presets it with a value. The counter then increments from this written
value upwards.
Note: If counters must be preset, they must be disabled in the RTIGCTRL register to ensure
consistency between RTIUC0 and RTIFRC0.
Note: If the preset value is bigger than the compare value stored in register RTICPUC0,
then it can take a long time until a compare matches, since RTIUC0 has to count up until
it overflows.