AN2690 Freescale Semiconductor / Motorola, AN2690 Datasheet - Page 20

• Manufacturer Part Number: AN2690
• Description: Low Frequency EEPROM Emulation on the MC68HLC908QY4
• Manufacturer: Freescale Semiconductor / Motorola

AN2690
LedDriver Flow
Diagram
20
Shift Bit to Left
DIRECTION =
LEFT
Low Frequency EEPROM Emulation on the MC68HLC908QY4
This routine controls the position of the illuminated LED. At reset, D8 (PTB3) is
lit. This is shifted to the left after each timeout (1000 ms). When D5 (PTB6) is
lit, the sequence is reversed, and the bit is shifted back to the right. This pattern
continues indefinitely.
Y
Freescale Semiconductor, Inc.
For More Information On This Product,
Shift Bit to Right
PTB3=1?
Go to: www.freescale.com
Figure 12. LED Driver
N
N
mask bits 6,5,4,3
Get PortB data
Shift Bit to Left
DIRECTION =
LedDriver
PTB6=1?
LEFT?
RTS
N
Y
Y
Shift Bit to Right
DIRECTION =
RIGHT
MOTOROLA