mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 755

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

34.4.6 MTIM16 modulo register low (MTIMx_MODL)
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 MITIM16 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_MODL is FFFF_8410h base + 5h offset = FFFF_8415h
34.5 Functional Description
The MTIM16 is composed of a main 16-bit up-counter with 16-bit modulo register, a
clock source selector, and a prescaler block with nine selectable values. The module also
contains software selectable interrupt logic.
Freescale Semiconductor, Inc.
MODL
Reset
Field
Read
7–0
Write
Bit
MTIM16 modulo (low byte)
These 8 read/write bits contain the modulo low 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_MODL field descriptions
0
5
Preliminary
0
4
Description
MODL
0
3
0
2
Chapter 34 Modulo Timer (MTIM)
0
1
0
0
755