Connect a 2.0-V reference source to V_REF/2, and repeat Problem 11-38.

Data from Problem 11-38

Refer to Figure 11-21. What is the approximate value of the analog input if the microcomputer’s data bus is at 10010111 when R̅D̅ is pulsed LOW?

Figure 11-21

Analog 0.5-3.5 V VREF IN REF Voc VREF Analog GND +5V supply 10 C 150 pF 0.5 V 1.5 V R 10 VIN(+) Voc V(-) VREF/2 Cik out Cik in CS WR RD (a) ADC0804 D De Voc Ds D4 D D D Do INTRO A GND D GND Data bus Digital GND AD1 Micro- processor AD AD AD4 AD3 AD Voc AD ADO CINTO RD WR GND [16] Address bus Address decoding logic