Filter
Top Products
Chapter 12 Serial Interface 3
Operation
XII - 36
Figure 12-3-15 Conditions Single Master IIC Communication Setup
(1) Select prescaler operation.
PSCMD (x'3F6F')
bp0 : PSCEN = 1
(2) Select the clock source.
SC2CKS (x'3FAF')
bp2-0 : SC3PSC2-0 = 100
bp3 = 0
(3) Control the pin type.
SC3ODC (x'3FAE')
bp1-0 : SC3ODC1-0 = 11
P5PLU (x'3F45')
bp2-1 : P5PLU2-1 = 1, 1
(4) Control the pin direction.
P5DIR (x'3F35')
bp2-1 : P5DIR2-1 = 1, 1
(1) Set the PSCEN flag of the PSCMD register to "1"
to select prescaler operation.
(2) Set the SC3PSC2-0 flag of the SC3CKS register
to "100" to select fs/2 at clock source.
Set bp3 of the SC3CKS register to "0", always.
(3) Set the SC3ODC1, 0 flag of the SC3ODC register
to "11" to select N-ch open drain for the SDA/
SCL pin type. Set the P5PLU2-1 flag of the
P5PLU register to "1, 1" to add pull-up resistor.
(4) Set the P5DIR2-1 flag of P5 pin control direction
register (P3DIR) to "1, 1" to set P52, P51, to
output mode.
An example setup procedure, with a description of each step is shown below.
12-3-4 Setup Example
Master Transmission Setup Example
Here is the setup example for the transmission of the plural data to the all devices on IIC bus with IIC
interface function of serial 3. Figure 12-3-15 shows the conditions.
Description
Setup Procedure
Item Set to Item Set to
SBI3/SBO3 pins
Connection
(with 2 lines)
Clock source fs/2
Transfer bit count 8 bits SCL/SDA pin's type N-ch open-drain
Start condition enable Pull-up resistance of SCL pin added
First transfer bit MSB Pull-up resistance of SDA pin added
ACK bit enable