mc9s08qg4 Freescale Semiconductor, Inc, mc9s08qg4 Datasheet - Page 147

• Manufacturer Part Number: mc9s08qg4
• Description: Hcs08 Microcontrollers Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

10.2
There are no ICS signals that connect off chip.
10.3
10.3.1
Freescale Semiconductor
IREFSTEN
IRCLKEN
IREFS
CLKS
Field
RDIV
7:6
5:3
2
1
0
Reset:
External Signal Description
Register Definition
W
R
ICS Control Register 1 (ICSC1)
Clock Source Select — Selects the clock source that controls the bus frequency. The actual bus frequency
depends on the value of the BDIV bits.
00
01
10
11
Reference Divider — Selects the amount to divide down the FLL reference clock selected by the IREFS bits.
Resulting frequency must be in the range 31.25 kHz to 39.0625 kHz.
000 Encoding 0 — Divides reference clock by 1 (reset default)
001 Encoding 1 — Divides reference clock by 2
010 Encoding 2 — Divides reference clock by 4
011 Encoding 3 — Divides reference clock by 8
100 Encoding 4 — Divides reference clock by 16
101 Encoding 5 — Divides reference clock by 32
110 Encoding 6 — Divides reference clock by 64
111 Encoding 7 — Divides reference clock by 128
Internal Reference Select — The IREFS bit selects the reference clock source for the FLL.
1 Internal reference clock selected
0 External reference clock selected
Internal Reference Clock Enable — The IRCLKEN bit enables the internal reference clock for use as
ICSIRCLK.
1 ICSIRCLK active
0 ICSIRCLK inactive
Internal Reference Stop Enable — The IREFSTEN bit controls whether or not the internal reference clock
remains enabled when the ICS enters stop mode.
1 Internal reference clock stays enabled in stop if IRCLKEN is set or if ICS is in FEI, FBI, or FBILP mode before
0 Internal reference clock is disabled in stop
entering stop
Output of FLL is selected.
Internal reference clock is selected.
External reference clock is selected.
Reserved, defaults to 00.
7
0
CLKS
Table 10-1. ICS Control Register 1 Field Descriptions
0
6
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 4
Figure 10-3. ICS Control Register 1 (ICSC1)
0
5
RDIV
0
4
Description
0
3
Chapter 10 Internal Clock Source (S08ICSV1)
IREFS
1
2
IRCLKEN
0
1
IREFSTEN
0
0
147