MEGA128CAN Datasheet, PDF (291/413 Pages) ATMEL Corporation – Microcontroller WITH 128K BYTES OF ISP FLASH AND CAN CONTROLLER

AT90CAN128
Capture-DR controller state. The Bypass Register may be used to shorten the scan
chain on a system when the other devices are to be tested.
Device Identification Register Figure 143 shows the structure of the Device Identification Register.
Figure 143. The Format of the Device Identification Register
Bit
Device ID
MSB
31
28 27
Version
4 bits
Part Number
16 bits
12 11
Manufacturer ID
11 bits
LSB
10
1
1-bit
Version
Version is a 4-bit number identifying the revision of the component. The relevant version
number is shown in Table 105.
Table 105. JTAG Version Numbers
Version
AT90CAN128 revision A
JTAG Version Number (Hex)
0x0
Part Number
Manufacturer ID
Device ID
The part number is a 16-bit code identifying the component. The JTAG Part Number for
AT90CAN128 is listed in Table 106.
Table 106. AVR JTAG Part Number
Part Number
AT90CAN128
JTAG Part Number (Hex)
0x9781
The Manufacturer ID is a 11-bit code identifying the manufacturer. The JTAG manufac-
turer ID for ATMEL is listed in Table 107.
Table 107. Manufacturer ID
Manufacturer
ATMEL
JTAG Manufactor ID (Hex)
0x01F
The full Device ID is listed in Table 108 following the AT90CAN128 version.
Table 108. Device ID
Version
AT90CAN128 revision A
JTAG Device ID (Hex)
0x0978103F
Reset Register
The Reset Register is a test data register used to reset the part. Since the AVR tri-states
Port Pins when reset, the Reset Register can also replace the function of the unimple-
mented optional JTAG instruction HIGHZ.
A high value in the Reset Register corresponds to pulling the external Reset low. The
part is reset as long as there is a high value present in the Reset Register. Depending
on the fuse settings for the clock options, the part will remain reset for a reset time-out
period (refer to “System Clock” on page 34) after releasing the Reset Register. The out-
4250E–CAN–12/04
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