Specification core processor 8052 core size 8-bit speed 16.78mhz connectivity i²c, spi, uart/usart ram size 17 number of i/o 8kb (8k x 8) program memory size flash program memory type 640 x 8 eeprom size 256 x 8 voltage - supply (vcc/vdd) 2.7 v ~ 5.5 v data converters a/d 6x12b; d/a 2x12b oscillator type internal operating temperature -40°c ~ 125°c package / case 28-tssop (0.173, 4.40mm width) .