mc68hc08az60 Freescale Semiconductor, Inc, mc68hc08az60 Datasheet - Page 325

• Manufacturer Part Number: mc68hc08az60
• Description: M68hc08 Family Of 8-bit Microcontroller Units Mcus
• Manufacturer: Freescale Semiconductor, Inc

Clock System
21-mscan
MOTOROLA
CGM
MSCAN08
OSC
Figure 7
and its interaction with the clock generation module (CGM). With this
flexible clocking scheme the MSCAN08 is able to handle CAN bus rates
ranging from 10 kbps up to 1 Mbps.
The clock source bit (CLKSRC) in the MSCAN08 module control register
(CMCR1) (see
defines whether the MSCAN08 is connected to the output of the crystal
oscillator or to the PLL output.
The clock source has to be chosen such that the tight oscillator tolerance
requirements (up to 0.4%) of the CAN protocol are met.
2
Freescale Semiconductor, Inc.
For More Information On This Product,
CGMXCLK
shows the structure of the MSCAN08 clock generation circuitry
Figure 7. Clocking Scheme
PLL
MSCAN Controller (MSCAN08)
CLKSRC
Go to: www.freescale.com
MSCAN08 Module Control Register 0
2
2
PRESCALER
(1 .. 64)
BCS
(2 * BUS FREQ.)
MSCAN Controller (MSCAN08)
MC68HC08AZ60 — Rev 1.0
on page 337)
MSCANCLK
CGMOUT
(TO SIM)
Clock System
325