CT-161-CD Fujitsu Semiconductor America Inc, CT-161-CD Datasheet - Page 50

• Manufacturer Part Number: CT-161-CD
• Description: KIT 16LX FOR MB90F387
• Manufacturer: Fujitsu Semiconductor America Inc
• Series: F²MC-16LXr
• Type: MCUr

Specifications of CT-161-CD

• Contents: Board, Cable, CD
• For Use With/related Products: MB90F387S
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 865-1103

Figure 2.7
2.4
The internal switch of microcomputer as shown in Figure 2.5 actually consists of a p-channel
type transistor and an n-channel type transistor as shown in Figure 2.7. The pin outputs a
low-level signal when the n-channel type transistor is in the on state; the pin outputs a
high-level signal when the p-channel type transistor is in the on state. You can switch the
output level of each port by setting the relevant value in the PDR1 register of the
microcomputer. In the example shown in Figure 2.7, '0' is written to the bit 0 of PDR1to set
pin P10 for low-level output, and '1' is written to the bit 1 of PDR1 to set pin P11 for
high-level output. With these settings, LED0 is turned on, and LED1 is turned off.
On the board, the LEDs are connected to pins P10 to P14. Therefore, the five pins are set to
the output mode for controlling the LEDs. When the microcomputer is reset, all bits of DDR
are reset to 0 (initial value), which means the ports are set to the input mode. In this status,
to use a pin as an output port, be sure to write '1' to the bit corresponding to the pin.
This section explain how to create a program that actually controls a microcomputer pin to
turn on an LED.
How to create and execute a program to turn on the LED
LED on/off control by rewriting the PDR1 register (with a conceptual diagram of the
Microcomputer
n-channel type
transistor ON
p-channel type
transistor ON
PDR1 bit1=1
PDR1 bit0=0
internal circuit of microcomputer)
-
44
Input
Output
Input
Output
-
DDR1 bit0=1
DDR1 bit1=1
1
0
0
1
Pin P10
Pin P11
LED0
On
LED1
Off
© Fujitsu