NXP Semiconductors
UM11227
NTM88 family of tire pressure monitor sensors
UM11227 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2020. All rights reserved.
User manual Rev. 6 — 24 April 2020
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10.22.3.4 SIM option 2 register (SIMOPT2)
Table 166. SIM option 2 register (SIMOPT2) (address $1803)
Bit 7 6 5 4 3 2 1 0
R 0
W —
COPT2 COPT1 COPT0 LFOSEL TCLKDIV BUSCLKS1 BUSCLKS0
Reset ($70) 0 1 1 1 0 0 0 0
Table 167. SIMOPT2 field descriptions
Field Description
6:4
COPT[2:0]
COPT[2:0] — COP Watchdog Timeout
The 3 bits COPT[2:0] write-once bits, with COPCLKS in SIMOPT1 select the timeout period of the COP.
When COPCLKS = 0 = COP clocked by LFO, ~1 ms COPT[2:0]
0 0 0 = 2
5
LFO bus cycles, ~32 ms
0 0 1 = 2
6
LFO bus cycles, ~64 ms
0 1 0 = 2
7
LFO bus cycles, ~128 ms
0 1 1 = 2
8
LFO bus cycles, ~256 ms
1 0 0 = 2
9
LFO bus cycles, ~512 ms
1 0 1 = 2
10
LFO bus cycles, ~1024 ms
1 1 0 = 2
11
LFO bus cycles, ~2048 ms; Result of Reset
When COPCLKS = 1 = COP clocked by system bus, which is itself selectable at ~2 µs, ~1 µs, ~0.5 µs, and
~0.25 µs.
COPT[2:0]
0 0 0 = 2
13
bus cycles
0 0 1 = 2
14
bus cycles
0 1 0 = 2
15
bus cycles
0 1 1 = 2
16
bus cycles
1 0 0 = 2
17
bus cycles
1 0 1 = 2
18
bus cycles
1 1 0 = 2
19
bus cycles
1 1 1 = 2
19
bus cycles; Result of Reset
3
LFOSEL
LFOSEL — LFO Selected
The LFOSEL selects the TPM channel 0 input to be connected to LFO or to the PTA2
0 = TPM channel 0 input connected to the PTA2; Result of Reset
1 = TPM channel 0 input connected to LFO
2
TCLKDIV
TCLKDIV — TPM External Clock Divider Enable
Enables divider by 8 of DX clock from RF module
0 = TPM External Clock source is the DX clock; Result of Reset
1 = TPM External Clock source is the DX clock divided by 8.
1:0
BUSCL
KS[1:0]
BUSCLKS[1:0] — BUS Clock Divider Selection
The 2 bits BUSCLKS[1:0] select the internal divisions to result in the desired system bus clock:
0 0 = 16 MHz / 2 = Core of 8 MHz and Bus of 4 MHz; Result of Reset
0 1 = 16 MHz / 4 = Core of 4 MHz and Bus of 2 MHz
1 0 = 16 MHz / 8 = Core of 2 MHz and Bus of 1 MHz
1 1 = 16 MHz / 16 = Core of 1 MHz and Bus of 0.5 MHz