Intel mcs-48 manual EM1

EM1

HARDWARE

The EM1 emulation board uses the 8748 to perform the emulation.

PO Simulator

Port 0 of the 8021 Is a quasi"-bldlrectlonal port. The PO simulator converts the data bus of the 8748 Into a quasi- bidirectional port.

Crystal Control Clock Buffer

The EM 1 allows user to select an on-board oscillator or a TTL clock driven from the 8021 user'sprototype system via a Camblon Suitcase jumper.

Jumper Poaltlon State

W1A- B On-Board

C-DExternal

TIL Clock

Zero Cross Detection Simulator

The zero cross detection simulator enables the 8748's T1 Input to detect zero-crossings. The circuitry provides a high level signal on a positive crossing and a low level signal on a negative crossing of zero to the T1 Input of the 8748.

Reset Buffer

The 8021 resets on a logic HIGH level signal. However, the 8748 resets on a logic LOW level, thus an Inverter Is provided on the EM1 to make the two chips compatible.

Optional Pull·Ups

Resistors are provided to simulate the optional pull-up resistors on T1 input and Port 0 of the 8021. A removable resistor pack is used on Port O. The T1 input pull up can be Installed by soldering In a 50K resistor.

"A bidirectional port which serves as an Input port. out- put port, or both even though outputs are statically latched.

Software

When emulating the 8021 with EM1, the user must observe the 8021 Instruction set.

DB0- DB7

P10 - P17

P20- P28

r-______________~A~LE~__________________~

40	8748					8021	28
	OR
						CABLE
LINES	4()'PIN		PROG				LINES
						PLUG
	PLUG	r-1
CABLE TO			CONTROL r-__________.......__-""XTAL 1				12 INCHES
ICE-49							FLAT CABLE
			CRYSTAL
MODULE			CLOCK
		Tlr-~-----.......----~		r-----------~--~Tl
	RESET t--.-----------------------o< 1------1---1RESET
				.	I
				RE~ET BUFFER	I	28·PIN
		'-oiiiCIAFiD. ,		r- -	-..,SOCKET
		I CLOCK	I	I OPTIONAL		I
		L2!!!I~ .J		LP~L~...J

10-18 AFN-00801A-02