Panasonic MN101C77C User Manual

Chapter 12    Serial Interface 3

Operation

XII - 36

(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.

„

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