mcf51ac256a Freescale Semiconductor, Inc, mcf51ac256a Datasheet - Page 375

• Manufacturer Part Number: mcf51ac256a
• Description: Mcf51ac Flexis
• Manufacturer: Freescale Semiconductor, Inc

16.3.3
Freescale Semiconductor
1
Field
TRIM
7:0
A value for TRIM is loaded during reset from a factory programmed location when not in any BDM mode. If in a BDM
mode, a default value of 0x80 is loaded.
W
R
MCG Trim Register (MCGTRM)
MCG Trim Setting — Controls the internal reference clock frequency by controlling the internal reference clock
period. The TRIM bits are binary weighted (i.e., bit 1 will adjust twice as much as bit 0). Increasing the binary
value in TRIM will increase the period, and decreasing the value will decrease the period.
An additional fine trim bit is available in MCGSC as the FTRIM bit.
If a TRIM[7:0] value stored in nonvolatile memory is to be used, it’s the user’s responsibility to copy that value
from the nonvolatile memory location to this register.
7
MCF51AC256 ColdFire Integrated Microcontroller Reference Manual, Rev. 5
Table 16-5. MCG Trim Register Field Descriptions
6
Figure 16-4. MCG Trim Register (MCGTRM)
5
4
Description
TRIM
1
3
Multipurpose Clock Generator (MCGV3)
2
1
0
16-7