mc9s08sg4 Freescale Semiconductor, Inc, mc9s08sg4 Datasheet - Page 162

• Manufacturer Part Number: mc9s08sg4
• Description: 8-bit Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

Chapter 11 Inter-Integrated Circuit (S08IICV2)
For example, if the bus speed is 8 MHz, the table below shows the possible hold time values with different
ICR and MULT selections to achieve an IIC baud rate of 100kbps.
162
MULT
Field
ICR
7–6
5–0
IIC Multiplier Factor. The MULT bits define the multiplier factor, mul. This factor, along with the SCL divider,
generates the IIC baud rate. The multiplier factor mul as defined by the MULT bits is provided below.
00 mul = 01
01 mul = 02
10 mul = 04
11 Reserved
IIC Clock Rate. The ICR bits are used to prescale the bus clock for bit rate selection. These bits and the MULT
bits determine the IIC baud rate, the SDA hold time, the SCL Start hold time, and the SCL Stop hold time.
Table 11-5 provides the SCL divider and hold values for corresponding values of the ICR.
The SCL divider multiplied by multiplier factor mul generates IIC baud rate.
SDA hold time is the delay from the falling edge of SCL (IIC clock) to the changing of SDA (IIC data).
SCL start hold time is the delay from the falling edge of SDA (IIC data) while SCL is high (Start condition) to the
falling edge of SCL (IIC clock).
SCL stop hold time is the delay from the rising edge of SCL (IIC clock) to the rising edge of SDA
SDA (IIC data) while SCL is high (Stop condition).
MULT
0x2
0x1
0x1
0x0
0x0
SCL Start hold time = bus period (s)
SCL Stop hold time = bus period (s)
Table 11-4. Hold Time Values for 8 MHz Bus Speed
SDA hold time = bus period (s)
MC9S08SG8 MCU Series Data Sheet, Rev. 3
Table 11-3. IICF Field Descriptions
0x0B
0x00
0x07
0x14
0x18
ICR
IIC baud rate
3.500
2.500
2.250
2.125
1.125
SDA
=
Description
-------------------------------------------- -
mul SCLdivider
bus speed (Hz)
×
×
×
×
mul
mul
mul
Hold Times (μs)
×
×
×
SCL Start
SDA hold value
SCL Start hold value
SCL Stop hold value
3.000
4.000
4.000
4.250
4.750
SCL Stop
5.500
5.250
5.250
5.125
5.125
Freescale Semiconductor
Eqn. 11-1
Eqn. 11-2
Eqn. 11-3
Eqn. 11-4