Rainbow Electronics ATmega162V - Manual (Page 212)

212
ATmega162/V
2513E–AVR–09/03
ATmega162 Boundary-
scan Order Table 88 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 pinout order as far as possible. Therefore, the
bits of Port A and Port E is scanned in the opposite bit order of the other ports. Excep-
tions 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 con-
nected to. In Figure 87, PXn. Data corresponds to FF0, PXn. Control corresponds to
FF1, and PXn. Pullup_enable corresponds to FF2. Bit 4, 5, 6, and 7of Port C is not in the
scan chain, since these pins constitute the TAP pins when the JTAG is enabled.
Table 87. Boundary-scan Signals for the Analog Comparator
Signal
Name
Direction as
seen from the
Comparator
Description
Recommended
Input when Not
in Use Output Values when
Recommended
Inputs are Used
AC_IDLE input Turns off Analog
comparator
when true 1 Depends upon µC
code being executed
ACO output Analog
Comparator
Output Will become
input to µC code
being executed 0
ACBG input Bandgap
Reference
enable 0 Depends upon µC
code being executed
Table 88. ATmega162 Boundary-scan Order
Bit Number Signal Name Module
105 AC_IDLE Comparator
104 ACO
103 ACBG
102 PB0.Data Port B
101 PB0.Control
100 PB0.Pullup_Enable
99 PB1.Data
98 PB1.Control
97 PB1.Pullup_Enable
96 PB2.Data
95 PB2.Control
94 PB2.Pullup_Enable
93 PB3.Data
92 PB3.Control
91 PB3.Pullup_Enable
90 PB4.Data
89 PB4.Control
88 PB4.Pullup_Enable