Specifications
Chapter 2: Board Components 2–15
Configuration, Status, and Setup Elements
© March 2009  Altera Corporation Cyclone III 3C120 Development Board Reference Manual
Configuration
This section discusses FPGA, flash memory, and MAX II device programming 
methods supported by the Cyclone III development board.
FPGA Programming Over USB
The FPGA can be configured at any time the board is powered on by using the 
USB 2.0 interface and the Quartus II Programmer in JTAG mode. 
The JTAG chain is mastered by the embedded USB Blaster function found in the 
MAX II device. Only a USB cable is needed to program the Cyclone III FPGA. Any 
device can be bypassed by using the appropriate switch on the JTAG control DIP 
switch. 
1 Board reference SW1 position 5 (SW1.5), labeled MAX0, must be in the closed position 
(on) for this feature to properly work. If the SW1 switch is in the closed position, the 
parallel flash loader (PFL) megafunction in the MAX II CPLD may try to overwrite 
the FPGA image just downloaded over the USB immediately after completion.
For more information about:
■ Advanced JTAG settings, refer to Table 2–7. 
■ The JTAG control switch, refer to “JTAG Control DIP Switch” on page 2–19.
The JTAG header can be used with an external USB-Blaster cable, or equivalent, to 
program either the MAX II CPLD or configure the Cyclone III FPGA. Most users of 
the Cyclone III development board do not use the JTAG header at all and instead use 
a USB cable along with the embedded USB-Blaster. Using an external USB-Blaster 
with the JTAG header requires disabling the embedded USB-Blaster function. See 
Ta bl e  2–7.
Figure 2–4.  JTAG Chain with the MAX II Device and the Cyclone III Device
2.5V 
2.5V 
2.5V 
HSMC Port A 
TDI 
TDO 
TMS 
TCK 
FPGA 
TDI 
TDO 
TMS 
TCK 
MAX II 
CPLD 
PSNTn 
HSMC Port B 
TDI 
TDO 
TMS 
TCK 
PSNTn 
TDI 
TDO 
TMS 
TCK 
GPIO Pins 
GPIO Pins 
GPIO Pins 
JTAG Control 
DIP Switch 
FPGA_BYPASS 
HSMA_BYPASS 
USB 2.0 
JTAG 
Header 
TDO 
TDI 
TMS 
TCK 
GPIO Pins 
Jumper 
DEV_SEL 
Jumper 
JTAG_SEL 
HSMA_BYPASS 
MAX_EN 










