MC9S12E128CFUE Datasheet, PDF (250/606 Pages) Freescale Semiconductor, Inc – MC9S12E128 Data Sheet

Chapter 8 Serial Communication Interface (SCIV3)
8.3.2.1 SCI Baud Rate Registers (SCIBDH and SCIBDL)
R
W
Reset
7
IREN
0
6
TNP1
5
TNP0
4
SBR12
3
SBR11
2
SBR10
0
0
0
0
0
Figure 8-3. SCI Baud Rate Register High (SCIBDH)
1
SBR9
0
0
SBR8
0
Table 8-1. SCIBDH Field Descriptions
Field
Description
7
IREN
Infrared Enable Bit — This bit enables/disables the infrared modulation/demodulation submodule.
0 IR disabled
1 IR enabled
6:5
Transmitter Narrow Pulse Bits — These bits determine if the SCI will transmit a 1/16, 3/16 or 1/32 narrow pulse.
TNP[1:0] Refer to Table 8-3.
4:0
SBR[11:8]
SCI Baud Rate Bits — The baud rate for the SCI is determined by the bits in this register. The baud rate is
calculated two different ways depending on the state of the IREN bit.
The formulas for calculating the baud rate are:
When IREN = 0 then,
SCI baud rate = SCI module clock / (16 x SBR[12:0])
When IREN = 1 then,
SCI baud rate = SCI module clock / (32 x SBR[12:1])
R
W
Reset
7
SBR7
0
6
SBR6
5
SBR5
4
SBR4
3
SBR3
2
SBR2
0
0
0
0
1
Figure 8-4. SCI Baud Rate Register Low (SCIBDL)
1
SBR1
0
0
SBR0
0
Table 8-2. SCIBDL Field Descriptions
Field
Description
7:0
SBR[7:0]
SCI Baud Rate Bits — The baud rate for the SCI is determined by the bits in this register. The baud rate is
calculated two different ways depending on the state of the IREN bit.
The formulas for calculating the baud rate are:
When IREN = 0 then,
SCI baud rate = SCI module clock / (16 x SBR[12:0])
When IREN = 1 then,
SCI baud rate = SCI module clock / (32 x SBR[12:1])
Read: anytime
MC9S12E128 Data Sheet, Rev. 1.07
250
Freescale Semiconductor