Specifications

22 Altera Corporation

EPXA1 Development Board Hardware Reference Manual

Difference Between Standard and Long Expansion Headers

On the standard expansion header, there is an RC-filtered connection to

EPXA1 device I/O pin AB5 from header pin J11.3. This circuit is suitable

for producing a high-impedance, low-precision analog output if the

appropriate pin is driven with a duty-cycle-modulated waveform by user

logic. However, there is no RC-filtered connection to an EPXA1 device

I/O pin from the long expansion header. Instead, header pin J4.3 supports

an additional user I/O.

EPXA1 Device Signal Definitions for the Expansion Headers

Table 13 on page 22 shows the definitions for the EPXA1 device signals

available to the standard expansion header interface. The definitions are

used with Altera daughter cards. The general purpose I/O signals can be

used as required.

See Table 24 on page 34 for standard expansion header pin-out details.

The long expansion header includes the signals in Table 13, plus the

additional signals in Figure 14.

Table 13. Standard Expansion Header Signal Definitions

Function Signals Number

General purpose I/O H5V_IO[40..0] 41

Clock H5V_OSC

H5V_CLK

H5V_CLKOUT

Bias voltage input H5V_VEE 1

Reset H5V_RST_N 1

Supply voltage VCC_5V

VCC_A

VCC_3V3

Table 14. Additional Signal Definitions for the Long Expansion Header

Function Signals Number

Address eup_A[15..0] 16

Data eup_D[15..0] 16

Supply voltage VCC_5V

VCC_A2

VCC_3V3