82C85
CMOS Static Clock Controller/Generator

Key Features

• Generates the System Clock For CMOS or NMOS Microprocessors and Peripherals
• Complete Control Over System Operation for Very Low System Power
• Stop-Oscillator
• Low Frequency
• Stop-Clock
• Full Speed Operation
• DC to 25MHz Operation (DC to 8MHz System Clock)
• Generates 50% and 33% Duty Cycle Clocks (Synchronized)
• Uses a Parallel Mode Crystal Circuit or External Frequency Source
• TTL Compatible Inputs/Outputs
• 24 Lead Slimline Dual-In-Line or 28 Pad Square LCC Package Options
• Single 5V Power Supply
• Operating Temperature Range
• C82C85 0^oC to +70^oC
• I82C85 -40^oC to +85^oC
• M82C85 -55^oC to +125^oC

Description

The Intersil 82C85 Static CMOS Clock Controller/Generator provides complete control of static CMOS system operating modes and supports full speed, slow, stop-clock and stop-oscillator operation. While directly compatible with the Intersil 80C86 and 80C88 16-bit Static CMOS Microprocessor Family, the 82C85 can also be used for general system clock control.

For static system designs, separate signals are provided on the 82C85 for stop (S0, S1, S2/STOP) and start (START) control of the crystal oscillator and system clocks. A single control line (SLO/FST) determines 82C85 fast (crystal/EFI frequency divided by 3) or slow (crystal/EFI frequency divided by 768) mode operation. Automatic maximum mode 80C86 and 80C88 software HALT instruction decode logic in the 82C85 enables softwarebased clock control. Restart logic insures valid clock startup and complete synchronization of system clocks.

The 82C85 is manufactured using the Intersil advanced Scaled SAJI IV CMOS process. In addition to clock control circuitry, the 82C85 also contains a crystal controlled oscillator (up to 25MHz), clock generation logic, complete "Ready" synchronization and reset logic. This permits the designer to tailor the system power-performance product to provide optimum performance at low power levels.