Datasheet

272
8011O–AVR–07/10
ATmega164P/324P/644P
22.6 ATmega164P/324P/644P Boundary-scan Order
Table 22-1 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 and Port K 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 regard-
less of which physical pin they are connected to. In Figure 22-3, PXn. Data corresponds to FF0,
PXn. Control corresponds to FF1, PXn. Bit 4, bit 5, bit 6 and bit 7 of Port F is not in the scan
chain, since these pins constitute the TAP pins when the JTAG is enabled.
Table 22-1. ATmega164P/324P/644P Boundary-scan Order
Bit Number Signal Name Module
56 PB0.Data
Port B
55 PB0.Control
54 PB1.Data
53 PB1.Control
52 PB2.Data
51 PB2.Control
50 PB3.Data
49 PB3.Control
48 PB4.Data
47 PB4.Control
46 PB5.Data
45 PB5.Control
44 PB6.Data
43 PB6.Control
42 PB7.Data
41 PB7.Control
40 RSTT Reset Logic (Observe Only)