CMOS Peripherals - - - - - - - - - - - - - - - - - - - - - - - - - - -
cr26 CN I
5 24 YR
6 23 ZR
7 22 BUS 7
8 21 BUS 6
9 20 BUS 5
10 19 BUS 4
II 18 BUS 3
12 17 BUS 2
13 16 suS I
14 15 BUSg
• Cascadable up to 4 units for 32-bit by 32-bit multiply or64 -7- 32 bit divide
• 8-blt by 8-bit multiply or 16 -7- 18 bit divide in 5.6 jJs at 5 Vor 2.8 jJs at 10 V
• Direct interface to CDP1800 series microprocessors
• Easy interface to other 8-bit microprocessors
• Significantly increases throughput of microprocessor used for
The RCA-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
multiple 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 of4 -10.5 volts, and the CDP1855C,
a recommended operating voltage range of 4 - 6.5 volts.
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).
NO RAO CI
NI RAI CNO
N2 RA2 CNI
E YL CDPI855
FIg. 1 - CIfCUlt confIguratIOn for MDU addressed as an 110 deVIce.
File Number 1053