MC9RS08KA2_08 Datasheet, PDF (75/136 Pages) Freescale Semiconductor, Inc – RS08 Microcontrollers

Chapter 9
Internal Clock Source (RS08ICSV1)
9.1 Introduction
The internal clock source (ICS) module provides clock source choices for the MCU. The module contains
a frequency-locked loop (FLL) as a clock source that is controllable by an internal reference clock. The
module can provide this FLL clock or the internal reference clock as a source for the MCU system clock,
ICSOUT.
Whichever clock source is chosen, ICSOUT is passed through a bus clock divider (BDIV), which allows
a lower final output clock frequency to be derived. ICSOUT is two times the bus frequency.
Figure 9-1 shows the MC9RS08KA2 Series block diagram with the ICS highlighted.
RS08 CORE
BDC
CPU
RS08 SYSTEM CONTROL
RESET AND STOP WAKEUP
MODES OF OPERATION
POWER MANAGEMENT
RTI
COP
WAKEUP
LVD
5-BIT KEYBOARD
INTERRUPT MODULE
(KBI)
ANALOG COMPARATOR
MODULE
(ACMP)
MODULO TIMER
MODULE
(MTIM)
5
ACMP+
ACMP-
TCLK
ACMPO
PTA0/KBIP0/ACMP+ ⁽¹⁾
PTA1/KBIP1/ACMP- ⁽¹⁾
PTA2/KBIP2/TCLK/RESET/V_PP ^{(1),( 2)}
PTA3/ACMPO/BKGD/MS
PTA4/KBIP4 ^(1),(3)
PTA5/KBIP5 ^{(1), (3)}
USER FLASH
MC9RS08KA2 — 2048 BYTES
MC9RS08KA1 — 1024 BYTES
USER RAM — 63 BYTES
INTERNAL CLOCK
SOURCE
(ICS)
V_SS
POWER AND
V_DD
INTERNAL REGULATOR
NOTES:
(1) Pins are software configurable with pullup/pulldown device if input port.
(2) Integrated pullup device enabled if reset enabled (RSTPE=1).
(3) These pins are not available in 6-pin package
Figure 9-1. MC9RS08KA2 Series Block Diagram Highlighting ICS Block
MC9RS08KA2 Series Data Sheet, Rev. 4
Freescale Semiconductor
75