CDP1878C

CDP1878C March 1997 CMOS Dual Counter-Timer Features Compatible with General Purpose and CDP1800 Series Microprocessor Systems Two 16-Bit Down Counters and Two 8-Bit Control Registers 5 Modes Including a Versatile Variable-Duty Cycle Mode Programmable Gate-Level Select Two-Complemented Output Pins for Each CounterTimer Software-Controlled Interrupt Output Addressable in Memory Space or CDP1800-Series I/O Space Ordering Information PART NUMBER CDP1878CE CDP1878CD TEMP. RANGE PACKAGE -40oC to +85oC PDIP -40oC to +85oC SBDIP PKG. NO. E28.6 N28.6 Description The CDP1878C is a dual counter-timer consisting of two 16bit programmable down counters that are independently controlled by separate control registers. The value in the registers determine the mode of operation and control functions. Counters and registers are directly addressable in memory space by any general industry type microprocessors, in addition to input/output mapping with the CDP1800 series microprocessors. Each counter-timer can be configured in five modes with the additional flexibility of gate-level control. The control registers in addition to mode formatting, allow software start and stop, interrupt enable, and an optional read control that allows a stable readout from the counters. Each countertimer has software control of a common interrupt output with an interrupt status register indicating which counter-timer has timed out. In addition to the interrupt output, true and complemented outpu...