When the ADC is enabled after being powered down (for example when waking up from HALT, ACTIVE-HALT or setting the ADON bit in the AD-CCSR register), the first conversion (8-bit or 10- bit) accuracy does not meet the accuracy specified in the data sheet.
IC, SM, MCU, 8-BIT; Series:ST72; Memory Size, Flash:16KB; Memory Size, RAM:768Byte; No of I/O Lines:23; No. of ADC Inputs:8; Timers, No. of:2; PWM Channels, No of:2; Clock Frequency:8MHz; Interface Type:SCI, SPI, USB; Voltage, Supply Min:4V; Voltage, Supply Max:5.5V; Termination Type:SMD; Case Style:SOIC; No. of Pins:34; Operating Temperature Range:0°C to +70°C