75
AT94KAL Series FPSLIC
Rev. 1138G–FPSLI–11/03
Part
Number
The part number is a 16 bit code identifying the component. The JTAG Part Number for AVR
devices is listed in Table 19.
Manufacturer ID
The manufacturer ID for ATMEL is 0x01F (11 bits).
AVR Reset
Register
The AVR Reset Register is a Test Data Register used to reset the AVR. A high value in the
Reset Register corresponds to pulling the external AVRResetn Low. The AVR is reset as long
as there is a high value present in the AVR Reset Register. Depending on the Bit settings for
the clock options, the CPU will remain reset for a Reset Time-Out Period after releasing the
AVR Reset Register. The output from this Data Register is not latched, so the reset will take
place immediately, see Figure 42.
Figure 42.
Reset Register
Boundary-scan Chain
The Boundary-scan Chain has the capability of driving and observing the logic levels on the
AVR’s digital I/O pins.
See “Boundary-scan Chain” on page 76 for a complete description.
Boundary-scan
Specific
JTAG Instructions
The instruction register is 4-bit wide, supporting up to 16 instructions. Listed below are the
JTAG instructions useful for Boundary-Scan operation. Note that the optional HIGHZ instruc-
tion is not implemented.
As a definition in this data sheet, the LSB is shifted in and out first for all shift registers.
The OPCODE for each instruction is shown behind the instruction name in hex format. The
text describes which data register is selected as path between TDI and TDO for each
instruction.
Table 19.
JTAG Part Number
Device
Part Number (Hex)
AT94K05
0xdd77
AT94K10
0xdd73
AT94K40
0xdd76
D
Q
From
TDI
ClockDR · AVR_RESET
To
TDO
From other internal and
external reset sources
Internal AVR Reset