EM6517 ETC, EM6517 Datasheet - Page 33

• Manufacturer Part Number: EM6517
• Description: 4 BIT MICROCONTROLLER
• Manufacturer: ETC

10 2-Channel ADC (8-bit digital converter)
The EM6517-1 contains one 8-bit ADC with 2 independent input channels. In addition one can choose also Vref
and Vgnd as ADC input. The control logic uses an internal analogue multiplexor to select the channel to be
converted. When data conversion is complete, indicated by a DATA VALID signal, the control logic saves the
converted value in the RegADCDataH and the Shadow Low registers. RegADCDataL registers is updated
when reading the RegADCDataH register. At the end of conversion an interrupt IRQADC is sent to the P. The
architecture of the ADC is illustrated in Figure 25.
Figure 25. ADC 8 Bit Architecture
Figure 26. ADC 8 Bit Timing
External
Start Convert
BIN
ADC Clock
V
AIN
V
Data Valid
IRQADC
DD
SS
Vref
Sample&Hold
Vgnd
VDD
1
2
0
3
1
2
Vref1
2
Vref2
FOR ENGINEERING ONLY
3
SVref1/2Sel Start
Channel
select
Control
8 clocks conversion
Logic
4
Vin
VrefInt
Vgnd
REDISTRIBUTION
5
8-BIT CHARGE
Convert
ADC CORE
Convert
6
RdHigh
RdLow
IRQ
7
4-Bit Internal Data Bus
Data Valid
Data[7 :1]
8
9
10
Re-sampling
8
© EM Microelectronic-Marin SA, 09/99, Rev. A/277
RegADCDataL
Shadow Low
RegADCDataH
The ADC 8 bit contains
an inherent sample and
hold function : the input
voltage is sampled during
acquisition
clock cycles) and is held
until
conversion.
conversion time is 10
clock cycles.
EM6517
the
4
IRQADC
Ck[16]
phase
RdLow
RdHigh
end
Total
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of