Cobham Gaisler AB
GRETH
The GRETH core implements a 10/100 Mbit/s Ethernet Media Access Controller (MAC) with AMBA host interface. The core implements the 802.3-2002 Ethernet standard. Receive and transmit data is autonomously transferred between the Ethernet MAC and the AMBA AHB bus using DMA transfers. Through the use of receive and transmit descriptors, multiple ethernet packets can be received and transmitted without CPU involvement. The GRETH supports the MII and RMII PHY interfaces. Hardware support is also provided for the EDCL UDP debugging protocol. For critical space applications, a fault-tolerant version of GRETH is available with full SEU protection of all RAM blocks.
The GRETH core can optionally include hardare support for he Ethernet Debug Communication Link (EDCL) protocol. EDCL provides read/write access to the AHB bus through ethernet using an UDP based protocol. It operates in parallel with the MAC DMA and does not interfere with the normal network traffic other than lowering performance.
The estimated resource utilization of the GRETH is:
The next figure shows the GRETH interfaces.
The following is a summary of the features:
- Implements the 802.3-2002 Ethernet standard
- 10/100 Mbit/s Ethernet Media Access Controller (MAC)
- Autonomous data transfer using descriptor controlled DMA
- Support for MII and RMII
- Optional hardware debugging using EDCL
- SEU protection of internal buffers