MC9S08GB32 Motorola, MC9S08GB32 Datasheet - Page 123

• Manufacturer Part Number: MC9S08GB32
• Description: Microcontrollers
• Manufacturer: Motorola

The filter registers show the filter value (FLT).
FLT — Filter Value
7.5.6
TRIM — ICG Trim Setting
Freescale Semiconductor
The FLT bits indicate the current filter value, which controls the DCO frequency. The FLT bits are
read only except when the CLKS bits are programmed to self-clocked mode (CLKS = 00). In
self-clocked mode, any write to ICGFLTU updates the current 12-bit filter value. Writes to the
ICGFLTU register will not affect FLT if a previous latch sequence is not complete.
The TRIM bits control the internal reference generator frequency. They allow a ± 25% adjustment of
the nominal (POR) period. The bit’s effect on period is binary weighted (i.e., bit 1 will adjust twice as
much as changing bit 0). Increasing the binary value in TRIM will increase the period and decreasing
the value will decrease the period.
ICG Trim Register (ICGTRM)
Reset:
Reset:
Read:
Write:
Read:
Write:
POR:
U = Unaffected by MCU reset
Figure 7-18. ICG Lower Filter Register (ICGFLTL)
Bit 7
U
1
7
1
Figure 7-19. ICG Trim Register (ICGTRM)
MC9S08GB/GT Data Sheet, Rev. 2.3
U
6
1
6
0
U
5
0
5
0
U
4
0
4
0
TRIM
FLT
U
3
0
3
0
U
2
0
2
0
ICG Registers and Control Bits
U
1
0
1
0
Bit 0
U
0
0
0
123