Local Bus Timer; Memory Map Of The Mc2 Chip Registers - Motorola MVME162FX Programmer's Reference Manual

Local Bus Timer

The MVME162FX provides a time-out 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 time-out value is selectable by software for 8 µsec, 64
µsec, 256 µsec, 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. Refer to
Example of the Proper Use of Bus Timers in Chapter 1 for more
information.
The access timer logic is duplicated in the VMEchip2 and MC2 chip
ASIC. Because the local bus timer in the VMEchip2 can detect an
off-board access and the MC2 chip local bus timer cannot, the timer
in the VMEchip2 is used in all cases except when the ÒNo VMEbus
InterfaceÓ option is enabled.

Memory Map of the MC2 chip Registers

The register map and address of the memory controller ASIC (MC2
chip) is documented in the following table. If the register is
depicted as a 32-bit entity, it must be accessed as a longword. If it is
accessed as a byte or word, the cycle is terminated with an error. If
the register is depicted as a 8- or 16-bit entity, it can be accessed as
a byte, word, or longword.
The base address of the register map is $FFF42000.
Memory Map of the MC2 chip Registers
3
3-9