CDP1855

Features:

• Cascadable Up to 4 Units for 32-Bit by 32-Bit Multiply or 64 ¸ 32-Bit Divide
• 8-Bit by 8-Bit Multiply or 16 ¸ 8-Bit Divide in 5.6ms at 5V or 2.8ms at 10V
• Direct Interface to CDP1800-Series Microprocessors
• Easy Interface to Other 8-Bit Microprocessors
• Significantly Increases Throughput of Microprocessor Used for Arithmetic Calculations


Pinout




Specifications

DC Supply Voltage Range, (VDD) (All voltage values referenced to VSS terminal) CDP1855 . . . . . . . . . . . . . . . -0.5V to +11V
CDP1855C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  . . . . . . . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to +7V
Input Voltage Range, All Inputs . . . . . . . . . . . . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.5V to VDD +0.5V
DC Input Current, Any One Input. . . . . . . . . . . . . . . . . . . . . . . . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±10mA


Description

The CDP1855 and CDP1855C are CMOS 8-bit multiply/ divide units which can be used to greatly increase the capabilities of 8-bit microprocessors. They perform multiply and divide operations on unsigned, binary operators. In general, microprocessors do not contain multiply or divide instructions and even efficiently coded multiply or divide subroutines require considerable memory and execution time. These multiply/divide units directly interface to the CDP1800-series microprocessors via the N-lines and can easily be configured to fit in either the memory or I/O space of other 8-bit microprocessors.
The multiple/divide unit is based on a method of multiplying by add and shift right operations and dividing by subtract and shift left operations. The device is structured to permit cascading identical units to handle operands up to 32 bits.
The CDP1855 and CDP1855C are functionally identical.
They differ in that the CDP1855 has a recommended operating voltage range of 4V to 10.5V, and the CDP1855C, a recommended operating voltage range of 4V to 6.5V.
The CDP1855 and CDP1855C types are supplied in a 28 lead hermetic dual-in-line ceramic package (D suffix) and in a 28 lead dual-in-line plastic package (E suffix). The CDP1855C is also available in chip form (H suffix).