beautypg.com

Atmega16(l) – Rainbow Electronics ATmega64L User Manual

Page 231

background image

231

ATmega16(L)

2466B–09/01

Note:

Incorrect setting of the switches in Figure 123 will make signal contention and may damage the part. There are several input
choices to the S&H circuitry on the negative input of the output comparator in Figure 123. Make sure only one path is selected
from either one ADC pin, Bandgap reference source, or Ground.

MUXEN_5

Input

Input Mux bit 5

0

0

MUXEN_4

Input

Input Mux bit 4

0

0

MUXEN_3

Input

Input Mux bit 3

0

0

MUXEN_2

Input

Input Mux bit 2

0

0

MUXEN_1

Input

Input Mux bit 1

0

0

MUXEN_0

Input

Input Mux bit 0

1

1

NEGSEL_2

Input

Input Mux for negative input for
differential signal, bit 2

0

0

NEGSEL_1

Input

Input Mux for negative input for
differential signal, bit 1

0

0

NEGSEL_0

Input

Input Mux for negative input for
differential signal, bit 0

0

0

PASSEN

Input

Enable pass-gate of gain stages.

1

1

PRECH

Input

Precharge output latch of
comparator. (Active low)

1

1

SCTEST

Input

Switch-Cap TEST enable. Output
from x10 gain stage send out to
Port Pin having ADC_4

0

0

ST

Input

Output of gain stages will settle
faster if this signal is high first two
ACLK periods after AMPEN goes
high.

0

0

VCCREN

Input

Selects Vcc as the ACC reference
voltage.

0

0

Table 91. Boundary-scan Signals for the ADC (Continued)

Signal
Name

Direction as Seen
from the ADC

Description

Recommended
Input when not
in Use

Output Values when Recommended
Inputs are used, and CPU is not
Using the ADC