General View

This document describes the 2TP_VME module, the final version (version MK4) of the two-transputer VME-module designed for the ZEUS experiment. The information a programmer needs to be able to use the module is contained in this document.

Detailed information about on-board switches and jumpers for hardware settings and a description of the frontpanel LEDs can be found in [1]. Examples (in OCCAM) of how to get the the transputers on the 2TP-VME module to do particular cycles are supplied in [3].

In the following the module will be referred to as the 2TP-VME. See figure 1 for a block scheme of the 2TP-VME.

The 2TP-VME features:

• two T800 or T425 transputers,
• 4 or 16 MByte of private memory (DRAM) per transputer,
• 128 or 512 kByte of Triple Port Memory (static RAM) :

  

  accessible by both transputers and from the VME-bus,

  

  locking of the arbiter for exclusive access by one transputer,

  

  Read-Modify-Write access from the VME-bus,

• VME-interface :

  

  access to the VME-bus by both transputers,

  

  memory-mapped VME cycle generation,

  

  implementation of most VME-cycle types, including Read-Modify-Write, Block Transfer indivisible cycles and Interrupt Acknowledge cycles,

  

  pipelined VME write cycles,

  

  a pipelined VME read cycle mode called Postfetch Mode,

  

  generation of VME Address Modifiers through programmable Address Modifier code registers (8 per transputer),

  

  generation of 4 upper address bits through a register (one per transputer) for full 4 GByte (32-bit) address range,

  

  routing of VME interrupt requests to the event input of one of the transputers and VME-bus errors to the transputer causing the bus error,

• external connections :

  

  RS-422 type balanced drivers/receivers for external connections of all 8 transputer links and additional logical signals via the P2 connector,

  

  routing of external signals to transputer event input,

• connection between the two transputers for mutual interrupt capability (no need to sacrifice transputer links for this),
• no need for external arbiter if the 2TP-VME is the only master in the VME-crate.

 
Figure 1: Block scheme of the 2TP-VME module.