2

VMEchip2

and monitor. On the local bus, the interrupt handler is designed to comply with the interrupt handling signaling protocol of the MC68060 microprocessor.

Global Control and Status Registers

The VMEchip2 includes a set of registers that are accessible from both the VMEbus and the local bus. These registers are provided to aid in interprocessor communications over the VMEbus. These registers are fully described in a later section.

LCSR Programming Model

This section defines the programming model for the Local Control and Status Registers (LCSR) in the VMEchip2. The local bus map decoder for the LCSR is included in the VMEchip2. The base address of the LCSR is $FFF40000 and the registers are 32-bits wide. Byte, two-byte, and four-byte read operations are permitted: however, byte and two-byte write operations are not permitted. Byte and two-byte write operations return a TEA signal to the local bus. Read-modify-write operations should be used to modify a byte or a two-byte of a register.

Each register definition includes a table with 5 lines:

Line 1 is the base address of the register and the number of bits defined in the table.

Line 2 shows the bits defined by this table.

Line 3 defines the name of the register or the name of the bits in the register.

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Motorola MVME172 manual Lcsr Programming Model, Global Control and Status Registers