Intel mcs-48 manual ====J, 123

inter

8041 AJ8641 AJ8741 A

UNIVERSAL PERIPHERAL INTERFACE

8·BIT MICROCOMPUTER

•8·Blt CPU plus ROM, RAM, 1/0, Timer and Clock in a Single Package

•One 8·Bit Status and Two Data Regis· ters for Asynchronous Slave·to·Master Interface

•DMA, Interrupt, or Polled Operation Supported

•1024)( 8 ROMIEPROM, 64)( 8 RAM, 8·Blt TimerlCounter, 18 Programmable 1/0 Pins

•Fully Compatible with MCS·48™, MCS.80™, MCS·85™, and MCS·86™ Microprocessor Families

•Interchangeable ROM and EPROM Versions

•3.6 MHz 8741A·8 Available

•Expandable 1/0

•RAM Power·Down Capability

•Over 90 Instructions: 70% Single Byte

•Single 5V Supply

The Intell!) 8041A18741A is a general purpose, programmable interface device designed for use with a variety of 8-bit microprocessor systems. It contains a low cost microcomputer with program memory, data memory, 8-bit CPU, I/O ports, timer/counter, and clock in a single 40-pin package. Interface registers are included to enable the UPI device to function as a peripheral controller in MCS-48™, MCS-80™, MCS-85™, MCS-86™, and other 8-bit systems.

The UPI-41ATM has 1K words of program memory and 64 words of data memory on-chip. To allow full user flexibility the program memory is available as ROM in the 8041A version or as UV-erasable EPROM in the 8741A version. The 8741A and the 8041 A are fully pin compatible for easy transition from prototype to production level designs. The 8641A is a one-time programmable (at the factory) 8741A which can be ordered as the first 25 pieces of a new.8041A order. The substitution of 8641A'sfor 8041A'sallows for very fast turnaround for initial code verification and evaluation results.

The device has two 8-bit, TTL compatible I/O ports and two test inputs. Individual port lines can function as either in- puts or outputs under software control. I/O can be expanded with the 8243 device which is directly .compatlble and has 16 I/O lines. An 8-bit programmable timer/counter is included in the UPI device for generating timing sequences or counting external inputs. Additional UPI features include: single 5V supply, low power standby mode (in the 8041A), single-step mode for debug (in the 8741A), and dual working register banks.

Because ifs a complete microcomputer, the UPI provides more flexibility for the designer than conventional LSI inter- face devices. It is·designed to be an efficient controller as well as an arithmetic processor. Applications include key- board scanning, printer control, display multiplexing and similar functions which involve interfacing peripheral devices to microprocessor systems.

PIN CONFIGURATION	BLOCK DIAGRAM
	INTERNAL
	BUS
	'0)

	::·¢:E::::;~~=~===~
MAITIR	-
SVSTEM
,.,
.........10lI - _
	01 --		PERIPHERAL
	..-	k;====:::J
			INTERFACE

SYNC

1Ii --

'"00

omT --

CR~~T~~{XTAL1__1 ,,1.. I

CLOCK XTAL2--

9-123 00188A