mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 754

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

Memory Map and Register Descriptions
34.4.5 MTIM16 modulo register high (MTIMx_MODH)
A value of 0x0000 in MODH:MODL puts the MTIM16 in free-running mode. Writing to
either MODH or MODL latches the value into a buffer and the latched buffers are
updated after the second byte writing. The updated values take effect and reload to the
MODH:MODL registers in the next MTIM16 counter cycle, except for the first writing
of modulo after a chip reset or in BDM mode. However, after a software reset, the
MODH:MODL takes effect at once even if it did not take effect before the reset. On the
first writing of MODH:MODL after chip reset, the counter is reset and the modulo takes
effect immediately. The latching mechanism may be manually reset by setting the TRST
bit of the SC register (whether BDM is active or not).
When BDM is active, the coherency mechanism is frozen so that the buffer latches
remain in the state they were in when the BDM became active, even if one or both halves
of the modulo register are written while BDM is active. Any writing to the modulo
registers bypasses the buffer latches and writes directly to the modulo register while
BDM is active, and also the counter is cleared at the same time.
Reading MODH:MODL returns the modulo values that are taking effect whenever in
normal run mode or in BDM mode.
Addresses: MTIM0_MODH is FFFF_8410h base + 4h offset = FFFF_8414h
754
MODH
CNTL
Field
Reset
Field
7–0
Read
7–0
Write
Bit
MTIM16 count (low byte)
These 8 read-only bits contain the current low byte value of the 16-bit counter. Writing has no effect on
this register. Reset clears the register to 0x00.
MTIM16 modulo (high byte)
These 8 read/write bits contain the modulo high byte value used to reset the counter and set TOF. Reset
sets the register to 0x00.
7
0
0
6
MCF51JF128 Reference Manual, Rev. 2, 03/2011
MTIM0_MODH field descriptions
MTIM0_CNTL field descriptions
0
5
Preliminary
0
4
Description
MODH
Description
0
3
0
2
Freescale Semiconductor, Inc.
0
1
0
0