UG-1262
Rev. B | Page 300 of 312
SNAPSHOT 1 REGISTER
Address: 0x40001434, Reset: 0x0000, Name: SNAP1
SNAP1 is a sticky snapshot of the value of CNT1. It is updated at the same time as its counterparts, SNAP0 and SNAP2, thereby
overwriting any previous value of SNAP1, SNAP0, and SNAP2. This updating and overwriting occurs when the CPU writes a snapshot
request key of 0x7627 to the GWY register.
Table 391. Bit Descriptions for SNAP1
Bits Bit
Name Settings Description
Reset Access
[15:0] VALUE
Contains a Sticky Snapshot of CNT1. This channel takes a sticky snapshot of the 47-bit WUT
count in CNT1, CNT0, and CNT2 and stores it in SNAP1, SNAP0, and SNAP2, respectively.
0x0 R
SNAPSHOT 2 REGISTER
Address: 0x40001438, Reset: 0x0000, Name: SNAP2
SNAP2 is a sticky snapshot of the value of CNT2. It is updated as the same time as its counterparts, SNAP0 and SNAP1, thereby overwriting any
previous values of SNAP1, SNAP0, and SNAP2 whenever the CPU writes a snapshot request key of 0x7627 to the GWY register.
Table 392. Bit Descriptions for SNAP2
Bits Bit
Name Settings Description
Reset Access
15 Reserved
Reserved.
0x0 R
[14:0] VALUE
Contains a Sticky Snapshot of CNT2. This channel takes a sticky snapshot of the 47-bit WUT
count in CNT1, CNT0, and CNT2 and stores it in SNAP1, SNAP0, and SNAP2, respectively.
0x0 R
MODULO REGISTER
Address: 0x4000143C, Reset: 0x0040, Name: MOD
MOD is a read only register that makes available CNTMOD60, the modulo 60 equivalent of the CNT1 and CNT0 count values. This
modulo 60 value is equal to the displacement in prescaled WUT time units past the most recent modulo 60 roll over event. A roll over is
a synonym for a modulo 60 boundary.
The WUT realigns itself to create coincident modulo 60 and modulo 1 boundaries whenever either of the following events occurs:
CPU writes a new pair of values to the CNT1 and CNT0 registers to redefine the elapsed time units count while the WUT is enabled
and this posted twin write is subsequently executed.
CPU enables the WUT from a disabled state using the CR0, Bit 0.
Other read only fields accessible via this register are the magnitude of the most recent increment to the WUT count (INCR) and
confirmation as to whether this increment coincided with a trim boundary. The same increment is applied by the WUT to both its
absolute (32-bit) count and the modulo 60 equivalent.
To facilitate debug and to clarify the relationship between CNTMOD60 and CNTx, the upper bits of MOD are padded with the LSBs of CNT0,
allowing CNTMOD60 and part of the main WUT count to be read out at the same time and their alignment with each other to be understood.
Table 393. Bit Descriptions for MOD
Bits
Bit
Name
Settings Description
Reset Access
[15:11] CNT0_4TOZERO
Mirror of CNT0, Bits[4:0]. These bits are a mirror of CNT0, Bits[4:0], made
available for simultaneous readback along with the CNTMOD60 bit field of
MOD. Having this mirror available at the same time allows the relationship
between the modulo 60 and absolute versions of the WUT count to be better
understood and debugged.
0x0 R
10 Reserved
Reserved.
0x0
R
[9:6] INCR
Most Recent Increment Value Added to the WUT Count in CNT1 and CNT0. INCR is
the read only value by which the WUT count has most recently been incremented.
Under normal circumstances, when the WUT is enabled, this value is one.
0x1 R