ARINC 429 Bus Interface

4

v5.0

Core429 clock rate can be programmed to be 1, 10, 16, or

20 MHz. All the Actel families listed above easily meet

the required performance.

Core429 I/O requirements depend on the system

requirements and the external interfaces. If the core and

memory blocks are implemented within the FPGA and

the CPU interface has a bidirectional data bus, then

approximately 74 I/O pins are required to implement

four Rx and four Tx modules. The core will require 62

pins to implement one Rx and one Tx module.

The core has various FIFO flags available for debugging

purposes. These flags may not be needed in the final

design and this will reduce the I/O count.

Memory Requirements

The number of memory blocks required differs, depending on whether each channel is configured the same or

differently.

Each Channel Configured the Same

Use EQ 1 to calculate the number of memory blocks required if each channel is configured the same.

Number of memory blocks = NRx * (INT (LABEL_SIZE/X) + INT (RX_FIFO_DEPTH/Y) + NTx * INT (FIFO_DEPTH/Y),

EQ 1

Table 3 •

Device Utilization for One Rx and One Tx Module

Cells or Tiles

Family

Combinatorial

Sequential

Total

Memory Blocks

Device

Utilization

Fusion

848

609

1,457

3

AFS600

10%

ProASIC3/E

848

609

1,457

3

A3PE600

10%

1,084

377

1,461

3

APA075

48%

Axcelerator

518

378

896

3

AX125

44%

RTAX-S

604

429

1,033

3

RTAX250S

24%

Table 4 •

Device Utilization for 16 Rx and 16 Tx Modules

Cells or Tiles

Family

Combinatorial

Sequential

Total

Memory Blocks

Device

Utilization

Fusion

13,435

9,614

23,049

48

AFS1500

60%

ProASIC3/E

13,435

9,614

23,049

48

A3PE1500

60%

16,835

5,928

22,763

48

APA750

69%

Axcelerator

8,044

5,944

13,988

48

AX2000

43%

RTAX-S

9,594

6,745

16,339

48

RTAX2000S

51%

Table 5 •

Device Utilization for Legacy Mode (2 Rx and 1 Tx)

Family

Cells or Tiles

Memory

Blocks

Device

Utilization

Combinational

Sequential

Total

Fusion

1,444

1,068

2,512

5

AFS600

18%

ProASIC3/E

1,444

1,068

2,512

5

A3PE600

18%

1,840

674

2,514

5

APA150

41%

Axcelerator

955

653

1,608

5

RTAX250S

20%

RTAX-S

1,062

729

1,791

5

RTAX250S

42%