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Atmega16 boundary- scan order, Atmega16(l) – Rainbow Electronics ATmega64L User Manual

Page 235

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235

ATmega16(L)

2466B–09/01

ATmega16 Boundary-
scan Order

Table 94 shows the Scan order between TDI and TDO when the Boundary-scan chain
is selected as data path. Bit 0 is the LSB; the first bit scanned in, and the first bit
scanned out. The scan order follows the pin-out order as far as possible. Therefore, the
bits of Port A is scanned in the opposite bit order of the other ports. Exceptions from the
rules are the Scan chains for the analog circuits, which constitute the most significant
bits of the scan chain regardless of which physical pin they are connected to. In Figure
116,
PXn. Data corresponds to FF0, PXn. Control corresponds to FF1, and PXn.
Pullup_enable corresponds to FF2. Bit 2, 3, 4, and 5 of Port C is not in the scan chain,
since these pins constitute the TAP pins when the JTAG is enabled.

Table 94. ATmega16 Boundary-scan Order

Bit Number

Signal Name

Module

140

AC_IDLE

Comparator

139

ACO

138

ACME

137

ACBG

136

COMP

ADC

135

PRIVATE_SIGNAL1

(Note:)

134

ACLK

133

ACTEN

132

ADHSM

131

ADCBGEN

130

ADCEN

129

AMPEN

128

DAC_9

127

DAC_8

126

DAC_7

125

DAC_6

124

DAC_5

123

DAC_4

122

DAC_3

121

DAC_2

120

DAC_1

119

DAC_0

118

EXTCH

117

G10

116

G20

115

GNDEN

114

HOLD

113

IREFEN