1. Embedded Network Interface (ENI)

2. What is ENI? Embedded Network Interface Originally called DPO (Digital Product Option) card Printer without network capability into interface with our network card Enable an external device with a processor to interface the NET+ARM The interface is used as a bridge to the LAN

3. More About ENI Allows sharing of NET+ARM’s memory system Useful for dual processor system Second Processor must push / pull data –NET+ARM is a slave in ENI mode Can use either FIFO mode or Shared Ram mode –FIFO is fast, but have less control over data –Shared RAM is slower, but have more control –ENI must become BUS Master to use Shared RAM ENI is muxed with Parallel Ports (one or the other)

4. Hardware Concept NetARM (Slave) host ENI Port Data + Addr Bus RAM External uP System (Master) client Data + Addr Bus

5. ENI Hardware DMA Hardware Module Transmit FIFO Shared RAM External Device ENI bi-directional data bus RAM Receive FIFO Channel 4Channel 3 NET+ARM ENI Hardware Peripheral

6. New GPIO ports on NET+50 ENI module in GPIO mode provides four 8-bit GPIO ports Two ports are I/O ports (Port D and Port F) and two ports are input ports (Port G and Port H) GPIO port pins are individually configurable to input, output, active high interrupt or active low interrupt Interrupts are level sensitive

7. GPIO Port Interrupts on NET+50 Port D uses interrupt 21 (ENI port 1) Port F uses interrupt 20 (ENI port 2) Port G uses interrupt 19 (ENI port 3) Port H uses interrupt 18 (ENI port 4)

8. Modes of Operation ENI Shared RAM – 16 bit interface ENI Shared RAM – 8 bit interface ENI FIFO – 16 interface with 8K Shared memory ENI FIFO – 8 interface with 8K Shared memory

9. Shared RAM Mode Allow external device (client) to random access external memory which is controlled by the the NET+ARM (host) 8/16-bit interface Size of Shared RAM is can be one of the following –4K, 8K, 16. 32, or 64K Location of RAM must be a multiple of the size selected –E.g. ram size of 8k must on located on a 8k boundary

10. FIFO Mode Data-streaming interface between the NET+ARM and the external device 8/16-bit interface Two 32-byte FIFOs used to transmit and receive data DMA 3 is used to transfer receive data from FIFO to external memory DMA 4 is used to transfer transmit data from external memory to FIFO DMA buffers must start and end on a 32-bit boundary Data must be padded to conform to buffer requirement 8K of shared memory can be accessed