s908gr32ag3vfa Freescale Semiconductor, Inc, s908gr32ag3vfa Datasheet - Page 177

• Manufacturer Part Number: s908gr32ag3vfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Use the following formula to calculate the ESCI baud rate:
where:
Table 13-11
13.9 ESCI Arbiter
The ESCI module comprises an arbiter module designed to support software for communication tasks as
bus arbitration, baud rate recovery and break time detection. The arbiter module consists of an 9-bit
counter with 1-bit overflow and control logic. The CPU can control operation mode via the ESCI arbiter
control register (SCIACTL).
Freescale Semiconductor
Frequency of the SCI clock source = f
BPD = Baud rate register prescaler divisor
BD = Baud rate divisor
PD = Prescaler divisor
PDFA = Prescaler divisor fine adjust
SCIBDSRC in the CONFIG2 register)
shows the ESCI baud rates that can be generated with a 4.9152-MHz bus frequency.
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
Table 13-10. ESCI Prescaler Divisor Fine Adjust (Continued)
PSSB[4:3:2:1:0]
1 0 0 0 0
1 0 0 0 1
1 0 0 1 0
1 0 0 1 1
1 0 1 0 0
1 0 1 0 1
1 0 1 1 0
1 0 1 1 1
1 1 0 0 0
1 1 0 0 1
1 1 0 1 0
1 1 0 1 1
1 1 1 0 0
1 1 1 0 1
1 1 1 1 0
1 1 1 1 1
Baud rate =
Frequency of the SCI clock source
64 x BPD x BD x (PD + PDFA)
Bus
16/32 = 0.5
17/32 = 0.53125
18/32 = 0.5625
19/32 = 0.59375
20/32 = 0.625
21/32 = 0.65625
22/32 = 0.6875
23/32 = 0.71875
24/32 = 0.75
25/32 = 0.78125
26/32 = 0.8125
27/32 = 0.84375
28/32 = 0.875
29/32 = 0.90625
30/32 = 0.9375
31/32 = 0.96875
or CGMXCLK (selected by
Prescaler Divisor Fine Adjust (PDFA)
ESCI Arbiter
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