Panasonic MN101C77C Manual De Usuario

Chapter 12    Serial Interface 3

Operation

XII - 24

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Transmission/Reception Setup Example

Here is the setup example for transmission/reception with serial interface 3. Table 12-3-10 shows the

conditions.

Description

(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 SBO3/

SBT3 pin's type. Set the P5PLU2-1 flag of the

P5PLU register to "1, 1" to add pull-up resistor.

(4)

Set the P5DIR2-0 flag of P5 pin control direction

register (P5DIR) to "110" to set P52, P51, to

output mode, to set P50 to input mode.

(5)

Set the SC3CMD flag of the serial 3 control

register (SC3CTR) to "0" to select synchronous

serial.

An example setup procedure, with a description of each step is shown below.

Setup Procedure

(1)

Select prescaler operation.

PSCMD (x'3F6F')

bp0 : PSCEN = 1

(2)

Select the clock source.

SC3CKS (x'3FAF')

bp2-0 : SC2PSC2-0 = 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')

bp2-0 : P5DIR2-0 = 110

(5)

Select the communication type.

SC3CTR (x'3FAA')

bp2 : SC3CMD = 0

Item

Set to

Item

Set to

SBI3/SBO3 pin

independent (with 3 lines) Clock

internal clock

Transfer bit count

8 bits

Clock source

fs/2

Start condition

enable

SBT3/SBO3 pin type

N-ch open-drain

First bit to be transfered

MSB

Pull-up resistance of SBT3 pin

added

Input edge

at falling

Pull-up resistance of SBO3 pin added

Output edge

at rising