Motorola MVME166D2 用户手册

Functional Description

1-17

Four 32-bit programmable tick timers with 1 

µ

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.  

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.  

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

The MVME166 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 

µ

sec, 64 

µ

sec, 256 

µ

sec, or infinite.  The local bus timer does not 

operate during VMEbus or VSB bound cycles.  VMEbus bound cycles are 
timed by the VMEbus access timer and the VMEbus global timer.  VSB bound 
cycles are timed by the VSB access timer, the VSB transfer timer, and if its serial 
arbiter is enabled, by the VSB arbitration timer.  

The MVME166 has two 96-position DIN connectors:  P1 and P2.  P1 rows A, B, 
C, and P2 row B provide the VMEbus interconnection.  P2 rows A and C, on 
the MVME166, provide the connection to the VSB.  The MVME166 has a 20-pin 
connector mounted behind the front panel. When the MVME166 board is 
enclosed in a chassis and the front panel is not visible, this connector allows 
the reset, abort and LED functions to be extended to the control panel of the 
system, where they are visible.  The MVME166 has a 68-pin mini D ribbon 
shielded connector for the SCSI bus interface.  The MVME166 has a 100-pin 
mini D ribbon shielded connector for the serial ports, Ethernet, and printer.