Datasheet

226

2503Q–AVR–02/11

ATmega32(L)

controller state. The Bypass Register can be used to shorten the scan chain on a system when

the other devices are to be tested.

Device Identification

Figure 114 shows the structure of the Device Identification Register.

Figure 114. The Format of the Device Identification Register

Version Version is a 4-bit number identifying the revision of the component. The JTAG version number

follows the revision of the device. Revision A is 0x0, revision B is x1 and so on.

Part Number The part number is a 16-bit code identifying the component. The JTAG Part Number for

ATmega32 is listed in Table 87.

Manufacturer ID The Manufacturer ID is a 11 bit code identifying the manufacturer. The JTAG manufacturer ID

for Atmel is listed in Table 88.

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 unimplemented 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 set-

tings for the clock options, the part will remain reset for a Reset Time-Out Period (refer to “Clock

Sources” on page 25) after releasing the Reset Register. The output from this Data Register is

not latched, so the reset will take place immediately, as shown in Figure 115.

MSB LSB

Bit 31 28 27 12 11 1 0

Device ID Version Part Number Manufacturer ID 1

4 bits 16 bits 11 bits 1 bit

Table 87. AVR JTAG Part Number

Part Number JTAG Part Number (Hex)

ATmega32 0x9502

Table 88. Manufacturer ID

Manufacturer JTAG Man. ID (Hex)

Atmel 0x01F