FTMx_SC field descriptions (continued)
Field
Description
000
Divide by 1
001
Divide by 2
010
Divide by 4
011
Divide by 8
100
Divide by 16
101
Divide by 32
110
Divide by 64
111
Divide by 128
12.3.4 Counter High (FTMx_CNTH)
The Counter registers contain the high and low bytes of the counter value. Reading either
byte latches the contents of both bytes into a buffer where they remain latched until the
other half is read. This allows coherent 16-bit reads in either big-endian or little-endian
order which makes this more friendly to various compiler implementations. The
coherency mechanism is automatically restarted by an MCU reset or any write to the
Status and Control register.
Writing any value to COUNT_H or COUNT_L updates the FTM counter with its initial
16-bit value (all zeroes) and resets the read coherency mechanism, regardless of the data
involved in the write.
When BDM is active, the FTM counter is frozen (this is the value that you may read); the
read coherency mechanism is frozen such that the buffer latches remain in the state they
were in when the BDM became active, even if one or both counter bytes are read while
BDM is active. This assures that if you were in the middle of reading a 16-bit register
when BDM became active, it reads the appropriate value from the other half of the 16-bit
value after returning to normal execution.
Address: Base a 1h offset
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
0
0
0
0
0
0
0
0
FTMx_CNTH field descriptions
Field
Description
COUNT_H
Counter value high byte
Chapter 12 FlexTimer Module (FTM)
MC9S08PA4 Reference Manual, Rev. 5, 08/2017
NXP Semiconductors
239
Summary of Contents for MC9S08PA4
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Page 2: ...MC9S08PA4 Reference Manual Rev 5 08 2017 2 NXP Semiconductors ...
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Page 28: ...System clock distribution MC9S08PA4 Reference Manual Rev 5 08 2017 28 NXP Semiconductors ...
Page 150: ...Port data registers MC9S08PA4 Reference Manual Rev 5 08 2017 150 NXP Semiconductors ...
Page 196: ...Human machine interfaces HMI MC9S08PA4 Reference Manual Rev 5 08 2017 196 NXP Semiconductors ...
Page 224: ...Instruction Set Summary MC9S08PA4 Reference Manual Rev 5 08 2017 224 NXP Semiconductors ...
Page 232: ...Functional Description MC9S08PA4 Reference Manual Rev 5 08 2017 232 NXP Semiconductors ...
Page 258: ...FTM Interrupts MC9S08PA4 Reference Manual Rev 5 08 2017 258 NXP Semiconductors ...
Page 294: ...Functional description MC9S08PA4 Reference Manual Rev 5 08 2017 294 NXP Semiconductors ...
Page 398: ...Resets MC9S08PA4 Reference Manual Rev 5 08 2017 398 NXP Semiconductors ...
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