EP3C16F256I7 Altera, EP3C16F256I7 Datasheet - Page 392

• Manufacturer Part Number: EP3C16F256I7
• Description: Cyclone III
• Manufacturer: Altera

IEEE 1149.1 (JTAG) Boundary-Scan Testing for Cyclone III Devices
14–18
Cyclone III Device Handbook, Volume 1
Notes to
(1)
(2)
EP3C120
Table 14–5. 32-Bit Cyclone III Device IDCODE
The most significant bit (MSB) is on the left.
The IDCODE’s least significant bit (LSB) is always 1.
Device
Table
14–5:
Version (4
0000
Bits)
USERCODE Instruction Mode
The USERCODE instruction mode is used to examine the UES within the
devices along an IEEE Std. 1149.1 chain. When this instruction is selected,
the device identification register is connected between the TDI and TDO
ports. The user-defined UES is shifted into the device ID register in
parallel from the 32-bit USERCODE register. The UES is then shifted out
through the device ID register.
1
CLAMP Instruction Mode
The CLAMP instruction mode is used to allow the state of the signals
driven from the pins to be determined from the boundary-scan register
while the bypass register is selected as the serial path between the TDI
and TDO ports. The state of all signals driven from the pins are completely
defined by the data held in the boundary-scan register.
1
HIGHZ Instruction Mode
The HIGHZ instruction mode sets all of the user I/O pins to an inactive
drive state. These pins are tri-stated until a new JTAG instruction is
executed. When this instruction is loaded into the instruction register, the
bypass register is connected between the TDI and TDO ports.
The UES value is not user defined until after the device is
configured. This is because the value is stored in the POF file and
only loaded to the device during configuration. Before
configuration, the UES value is set to the default value.
If you are testing after configuring the device, the
programmable weak pull-up resistor or the bus hold feature
overrides the CLAMP value (the value stored in the update
register of the boundary-scan cell) at the pin.
Part Number (16 Bits)
0010 0000 1111 0111
IDCODE (32 Bits)
Identity (11 Bits)
(1)
000 0110 1110
Manufacturer
Altera Corporation-Preliminary
LSB (1 Bit)
March 2007
1
(2)