Motorola MPC860 PowerQUICC User Manual page 428

Part IV. Hardware Interface
Ñ Write-protection capability
Ñ Address types protection for memory bank accesses by internal masters
Ñ Control signal generation machine selection on a per-bank basis
Ñ Support for external master access to memory banks
Ñ Synchronous and asynchronous external masters support
¥ General-purpose chip-select machine (GPCM)
Ñ Compatible with SRAM, EPROM, FEPROM, and peripherals
Ñ Global (boot) chip-select available at system reset
Ñ Boot chip-select support for 8-, 16-, and 32-bit devices
Ñ Minimum two clock accesses to external device
Ñ Four byte write enable signals (WE)
Ñ Output enable signal (OE)
¥ Two user-programmable machines
Ñ Programmable-array-based machine controls external signal timing with a
granularity of one quarter of an external bus clock period
Ñ User-speciÞed control-signal patterns run when an internal or external
synchronous master requests a single-beat or burst read or write access.
Ñ User-speciÞed control-signal patterns run when an external asynchronous master
requests a single-beat read or write access.
Ñ UPM periodic timer runs a user-speciÞed control signal pattern to support
refresh
Ñ User-speciÞed control-signal patterns can be initiated by software
Ñ Each UPM can be deÞned to support DRAM devices with depths of 64, 128, 256,
and 512 Kbytes, and 1, 2, 4, 8, 16, 32, 64, 128, and 256 Mbytes
Ñ Each UPM provides programmable timing for the following signals:
Ð Four byte-select lines
Ð Six external general-purpose lines
Ñ Supports 8-, 16-, and 32-bit DRAM port sizes
Ñ Glueless interface to one bank of DRAM (only external buffers are required for
additional SIMM banks)
Ñ Page mode support for successive transfers within a burst for all on-chip and
external synchronous devices
Ñ Internal address multiplexing for all on-chip bus masters supporting 64-, 128-,
256-, and 512-Kbyte, and 1-, 2-, 4-, 8-, 16-, 32-, 64-, 128-, 256-Mbyte page
banks
Ñ Glueless interface to EDO, self refresh, and synchronous DRAM devices
16-2 MPC860 PowerQUICC UserÕs Manual MOTOROLA