IBM EM78M611E manual Analog-To-Digital Converter ADC, Clock Hz Period/255 s

EM78M611E

Universal Serial Bus Series Microcontroller

ERE [0~2] PWM Clock Prescaler

PS2	PS1	PS0	Clock (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

Product Specification (V1.11) 04.20.2007 • 29

(This specification is subject to change without further notice)