IBM EM78M611E 8.11 Analog-To-Digital Converter (ADC)

EM78M611E
Universal Serial Bus Series Microcontroller
Product Specification (V1.11) 04.20.2007
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(This specification is subject to change without further notice)
ERE [0~2] PWM Clock Prescaler
PS2 PS1 PS0 Cloc k (Hz) Period/255 (s)
0 0 0 Fosc/3 0.5µ
0 0 1 Fosc/6 1µ
0 1 0 Fosc/12 2µ
0 1 1 Fosc/24 4µ
1 0 0 Fosc/48 8µ
1 0 1 Fosc/96 16µ
1 1 0 Fosc/192 32µ
1 1 1 Fosc/384 64µ
ERE [6, 7] PWM1/PWM2 Enable Bit
0 : Disable
1 : Enable
8.11 Analog-To-Digital Converter (ADC)
8.11.1 Function Description
The Analog to Digital converter consists of a 5-bit analog multiplexer, one Control
Register (ERA), and two data registers (RBS & RCS) for 10-bit resolution.
The ADC module utilizes successive approximation to convert the unknown analog
signal to a digital value. The result is fed to the ADDATA. Input channels are selected
by the analog input multiplexer via the ADCS/RAS bits AD0~AD4.
10-bit resolution: 0x00-00~0xC0-FF (0b11000000-11111111)
Start (0x00-00): 0 Vref~(1/1024) × Vref
Full (0xC0-FF): (1023/1024) × Vref~Vref
Conversion Time: 12 clock time of internal clock source
8.11.2 Control Register
ERA (AD Channel Select Register) Default Value: (0B_0001_1111)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
ADC 0 0 AD4 AD3 AD2 AD1 AD0