Datasheet

MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
Freescale Semiconductor 225
Figure 12-17. SLCBT Value Calculation Example 1
Figure 12-18. SLCBT Value Calculation Example 2
Figure 12-19. SLCBT Value Calculation Example 3
2 Clock Out Period
42.67 SLIC Clock Periods
1 SLIC Clock Period
1 SLIC Clock Period
X
=
406.901 ns 1 Bit
1 SLIC Clock Period
=
406.901 ns
1 Second
57,600 Bits
=
17.36111 μs
1 Bit
4,915,200 Clock Out Period
1 Second
X
17.36111 μs
1 Bit
Desired Bit Rate: 57,600 bps
External Crystal Frequency: 4.9152 MHz
Therefore, the closest SLCBT value would be 43 SLIC clocks (SLCBT = 0x002B).
Because you can only use even values in SLCBT, the closest acceptable value is 42 (0x002A).
2 Clock Out Period
85.33 SLIC Clock Periods
1 SLIC Clock Period
1 SLIC Clock Period
X
=
203.45 ns 1 Bit
1 SLIC Clock Period
=
203.45 ns
1 Second
57,600 Bits
=
17.36111 μs
1 Bit
9,830,400 Clock Out Periods
1 Second
X
17.36111 μs
1 Bit
Desired Bit Rate: 57,600 bps
External Crystal Frequency: 9.8304 MHz
Therefore, the closest SLCBT value would be 85 SLIC clocks (SLCBT = 0x0055).
Because you can only use even values in SLCBT, the closest acceptable value is 86 (0x0056)
2 Clock Out Period
256 SLIC Clock Periods
1 SLIC Clock Period
1 SLIC Clock Period
X
=
250 ns 1 Bit
1 SLIC Clock Period
=
250 ns
1 Second
15,625 Bits
=
64 μs
1 Bit
8,000,000 Clock Out Periods
1 Second
X
64 μs
1 Bit
Desired Bit Rate: 15,625 bps
External Crystal Frequency: 8.000 MHz
Therefore, the closest SLCBT value would be 256 SLIC clocks (SLCBT = 0x0100).