Motorola MVME187 Local Resources, Programmable Tick Timers, Watchdog Timer, Local Bus Timeout

Functional Description

Local Resources

The MVME187 includes many resources for the local processor. These include tick timers, software programmable hardware interrupts, watchdog timer, and local bus timeout.

Programmable Tick Timers

Four 32-bit programmable tick timers with 1 ∝s resolution are provided, two in the VMEchip2 and two in the PCCchip2. The tick timers can be programmed to generate periodic interrupts to the processor.

Watchdog Timer

A watchdog timer function is provided in the VMEchip2. When the watchdog timer is enabled, it must be reset by software within the programmed time or it times out. The watchdog timer can be programmed to generate a SYSRESET signal, local reset signal, or board fail signal if it times out.

Software-Programmable Hardware Interrupts

Eight software-programmable hardware interrupts are provided by the VMEchip2. These interrupts allow software to create a hardware interrupt.

Local Bus Timeout

The MVME187 provides a timeout function for the local bus. When the timer is enabled and a local bus access times out, a Transfer Error Acknowledge (TEA) signal is sent to the local bus master. The timeout value is selectable by software for 8 ∝sec, 64 ∝sec, 256 ∝sec, or infinite. The local bus timer does not operate during VMEbus bound cycles. VMEbus bound cycles are timed by the VMEbus access timer and the VMEbus global timer.

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