BOARD LAYOUT: POWER SUPPLY CIRCUIT: AVR-P28 isypically power supplied with min 9.0V DC max 12.0V DC, or min 6.0V AC max 9.0V AC. RESET CIRCUIT: AVR-P28 reset circuit includes pin 5 of ICSP connector, pin 1 of U1, Reset scheme – Features • High Performance, Low Power Atmel® AVR® 8-Bit Microcontroller † Advanced RISC Architecture – 135 Powerful Instructions – Most Single Clock Cycle Execution ...

T89C51RB2/RC2 is a high-performance FLASH version of the 80C51 8-bit microcon- trollers. It contains a 16K or 32K byte Flash memory block for program and data. The Flash memory can be programmed either in parallel mode or in serial mode with the ISP capability or with software. 33 XTAL1 (CLKIN) 24MHz Crystal or external clock input This pin can be connected to one terminal of the crystal or it can be connected to an external 24 clock when a crystal is not used 32 XTAL2 24MHz Crystal This is the other terminal of the crystal, or it is left open when an external clock source is used to drive XTAL1(CLKIN).