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HC908QB/QC Li'lBoard page.
Model number: LB4.01.
Description: A small Freescale processor in a 16 pin SOIC package.
Applications: The 'QB and 'QC both have an RS-232-timed serial port and an SPI port. These allow the L'il4.01 to be used to receive commands from a computer via a L'il6.01 USB or other source of RS-232, and control a large number of SPI devices.
Features: All of the QB/QC processors in the 16 pin packages provide 14 I/O signals (although one is input only). This family was selected for the L'ilboard line-up because both serial (RS-232 timed) and SPI ports are provided in silicon. The LIN protocol is also supported by the serial port.
The number of I/O pins available for actual I/O use can be maximized since the pins used for /IRQ, /RST and clock input/output can all be used as I/O instead.
These processors have the ability to self clock at up to 12.8 ('QB) or 25.6 ('QC) MHz. They can also be set up to run with a crystal (multiple values in three ranges including 32 kHz watch crystals) or have their frequency determined by a single external resistor. In all cases the CPU (instruction) clock is one quarter of the oscillator's frequency.
An on-board LED can be used as a basic power-on indicator or can be tied to a port pin to be under software control. SJ1 (bottom side) controls this, but a jumper wire has to be added from the terminal marked “LED” to the desired port pin if a port is to control the LED.
Key components: HC908QB in a 16-SOIC
Images:
SPI: Potential host.
Tenth centers: Partial