MC908QL4 FREESCALE [Freescale Semiconductor, Inc], MC908QL4 Datasheet - Page 166

• Manufacturer Part Number: MC908QL4
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Slave LIN Interface Controller (SLIC) Module
This resolution affects the sampling accuracy of the SLIC module on receiving bytes, but only as far as
locating the sample point of each bit within a given byte. The best sample point of the bit may be off by
as much as one SLIC clock period from the exact center of the bit, if the proper SLCBT value for the
desired bit rate is an odd number of SLIC clock periods.
166
Desired Bit Rate:
External Crystal Frequency:
Therefore, the closest SLCBT value would be 42 SLIC clocks (SLCBT = 0x00D0).
8,000,000 CGMXCLK Periods
Desired Bit Rate:
External Crystal Frequency:
Therefore, the closest SLCBT value would be 42 SLIC clocks (SLCBT = 0x002A).
Desired Bit Rate:
External Crystal Frequency:
Therefore, the closest SLCBT value would be 128 SLIC clocks (SLCBT = 0x0080).
9,830,400 CGMXCLK Periods
8,000,000 CGMXCLK Periods
1 Second
1 Second
1 Second
Figure 14-19. SLCBT Value Calculation Example 2
Figure 14-20. SLCBT Value Calculation Example 3
Figure 14-21. SLCBT Value Calculation Example 4
104.004 ms
17.36111 ms
1 Bit
1 Bit
64 ms
1 Bit
MC68HC908QL4 Data Sheet, Rev. 7
9.615 bps
8.000 MHz
57,600 bps
15,625 bps
9.8304 MHz
8.000 MHz
X
X
X
X
X
X
1 SLIC Clock Period
1 SLIC Clock Period
4 CGMXCLK Period
4 CGMXCLK Period
1 SLIC Clock Period
1 SLIC Clock Period
4 CGMXCLK Period
1 SLIC Clock Period
1 SLIC Clock Period
406.90 ns
500 ns
500 ns
9,615 Bits
1 Second
57,600 Bits
15,625 Bits
1 Second
1 Second
=
=
=
=
=
=
=
=
=
1 SLIC Clock Period
208.008 SLIC Clock Periods
104.004 ms
1 SLIC Clock Period
1 SLIC Clock Period
17.36111 ms
42.67 SLIC Clock Periods
64 ms
128 SLIC Clock Periods
1 Bit
1 Bit
1 Bit
406.90 ns
500 ns
500 ns
1 Bit
1 Bit
1 Bit
Freescale Semiconductor