Intel 8XC196NT User Manual page 500

AD_COMMAND
The A/D command (AD_COMMAND) register selects the A/D channel number to be converted,
controls whether the A/D converter starts immediately or with an EPA command, and selects the
conversion mode.
7
— —
Bit Bit
Number Mnemonic
7:6 —
5:4 M1:0
3 GO
2:0 ACH2:0
NOTES:
1. While a threshold-detection mode is selected for an analog input pin, no other conversion can be
started. If another value is loaded into AD_COMMAND, the threshold-detection mode is disabled
and the new command is executed.
2. It is the act of writing to the GO bit, rather than its value, that starts a conversion. Even if the GO
bit has the desired value, you must set it again to start a conversion immediately or clear it again
to arm it for an EPA-initiated conversion.
M1 M0
Reserved; for compatibility with future devices, write zeros to these bits.
A/D Mode (Note 1)
These bits determine the A/D mode.
M1 M0 Mode
0 0 10-bit conversion
0 1 8-bit conversion
1 0 threshold detect high
1 1 threshold detect low
A/D Conversion Trigger (Note 2)
Writing this bit arms the A/D converter. The value that you write to it
determines at what point a conversion is to start.
1 = start immediately
0 = EPA initiates conversion
A/D Channel Selection
Write the A/D conversion channel number to these bits. The 8XC196NT
has four A/D channel inputs, numbered 4–7.
Address:
Reset State:
GO ACH2 ACH1
Function
REGISTERS
AD_COMMAND
1FACH
C0H
0
ACH0
C-5