mpc82g516a Megawin Technology, mpc82g516a Datasheet - Page 82

• Manufacturer Part Number: mpc82g516a
• Description: 8-bit Microcontroller
• Manufacturer: Megawin Technology

(1,0,1): select AIN5 (P1.5) as the analog input
(1,1,0): select AIN6 (P1.6) as the analog input
(1,1,1): select AIN7 (P1.7) as the analog input
AUXR (Address=8EH, Auxiliary Register, Reset Value=0000,xx0xB)
ADRJ:
0: The most significant 8 bits of conversion result are saved in ADCH[7:0], while the least significant 2 bits in
1: The most significant 2 bits of conversion result are saved in ADCH[1:0], while the least significant 8 bits in
If ADRJ=0
ADCH (Address=C6H, ADC Result High-byte Register, Reset Value=xxH)
ADCL (Address=BEH, ADC Result Low-byte Register, Reset Value=xxH)
If ADRJ=1
ADCH (Address=C6H, ADC Result High-byte Register, Reset Value=xxH)
ADCL (Address=BEH, ADC Result Low-byte Register, Reset Value=xxH)
16.2 ADC Operation
For consideration of pin-compatible with the standard 8051 MCU, the ADC hardware cannot have separated
input pins for internal positive (Vref+) and negative (Vref-) reference voltages. The Vref+ and Vref- inputs have
been internally tied to VDD pin and ground, respectively. So, the full-scale voltage Vref+ – Vref- becomes VDD.
The A/D conversion result can be calculated from the following formula:
Where, Vin is the analog input voltage and x = 0~7 (any pin of AIN0~AIN7).
The input analog voltage should be between Vref+ and Vref-, i.e., VDD and ground. For input voltages between
Vref- and Vref- + 1/2 LSB, the 10-bit conversion result will be 00,0000,0000B = 000H. For input voltages between
Vref+ – 3/2 LSB and Vref+, the conversion result will be 11,1111,1111B = 3FFH. Where:
MEGAWIN
URTS
ADCL[1:0].
ADCL[7:0].
(B9)
(B7)
7
7
7
7
7
-
-
ADC Result = 1024 x
1 LSB =
ADRJ
(B8)
(B6)
6
6
6
6
6
-
-
Vref+
1024
P41ALE P35ALE
(B7)
(B5)
-
5
5
5
5
5
-
-
Vref-
Vref+
Vin
=
(B6)
(B4)
4
4
4
4
4
-
-
-
VDD
1024
Vref-
-
Vref-
MPC82G516A Data Sheet
(B5)
(B3)
3
-
3
3
3
3
-
-
=
AIN Analog Input Voltage
x
(B4)
(B2)
VDD Voltage
2
-
2
2
2
2
-
-
EXTRAM
(B3)
(B1)
(B9)
(B1)
1
1
1
1
1
(B2)
(B0)
(B8)
(B0)
0
0
0
0
0
-
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