Intel mcs-48 manual Psen, XTAL1, XTAL2, Family Development System and Software Support

inter8031/8051/8751

input during EPROM programming.

PSEN

The Program Store Enable output is a control signal that enables the external Program Memory to the bus during normal fetch operations.

EAIVOO

When held at a TTL high level, the 8051 executes instructions from the internal ROM/EPROM when the PC is less than 4096. When held at a TTL low level, the 8051 fetches all instuctions from external Program Memory. The pin also receives the 21V EPROM programming supply voltage.

XTAL1

Input to the oscillator'shigh gain amplifier. A crystal or external source can be used.

XTAL2

Output from the oscillator'samplifier. Required when a crystal is used.

assembly language instructions into machine exe- cutable object code. These assembly language mnemonics are easier to program and are more readable than binary or hexidecimal machine in- structions. Also, by allowing the programmer to give symbolic names to memory locations rather than absolute addresses, software design and debug are performed more quickly and reliably.

ASM51 provides symbolic access forthe many use- ful addressing methods in the 8051 architecture which reference bit, nibble and byte locations.

The assembler supports macro definitions and calls. This provides a convenient means of program- ming a frequently used code sequence only once. The assembler also provides conditional assembly capabilities. Cross referencing is provided in the symbol table listing, which shows the user the lines in which each symbol was defined and referenced.

If an 8051 program contains errors, the assembler provides a comprehensive set of error diagnostics, which are included in the assembly listing.

The object code generated may be used to program the 8751 EPROM version of the chip or sent to Intel for fabricating the 8051 ROM version. The assembler output can also be debugged using the ICE-51 in-circuit emulator.

8051 FAMILY DEVELOPMENT SYSTEM AND SOFTWARE SUPPORT

The 8051 is supported by a total range of Intel de- velopment tools. This broad range of support shortens the product development cycle and thus brings the product to market sooner.

•ASM51 Absolute macro assemblerfor the 8051.

•CONV51 8048 assembly language source code to 8051 assembly source code conver- sion program.

•EM-51 ,8051/8751emulator board that uses a modified 8051 and an EPROM.

•ICE-51'· Real-time in-circuit emulator.

•UPP-8051 PROM programmer personality card.

•8051 Workshop.

8051 Software Development Package (ASM51 and CONV51)

The 8051 software development package provides development system support for the powerful 8051 family of single chip microcomputers. The package contains a symbolic macro assembler and a 8048 to 8051 source code converter. This diskette-based software package runs under ISIS-II on any Intellec® Microcomputer Development System with 64K bytes of memory.

8051 Macro Assembler (ASM51)

The 8051 macro assembler translates symbolic 8051

8048 to 8051 Assembly Language Converter Utility Program (CONV51)

The 8048 to 8051 assembly language converter is a utility to help users of the MCS-48 family of micro- computers upgrade their designs to the high per- formance 8051 architecture. By converting 8048 source code to 8051 source code, the investment in software developed for the 8048 is maintained when the system is upgraded.

8051 Emulation Board (EM-51)

The EM-51 8051 emulation board is a small (2.85" x 5.25") board which emulates an 8031/8051/8751 microcomputer using standard PROMs or EPROMs in place of the 8051'son-chip program memory. The board includes a modified 8051 microcomputer, supporting circuits, and two sockets for program memory. The user may select two 2716 EPROMs, a 2732 EPROM, or two 3636 bipolar PROMs depend- ing on crystal frequency and power requirements.

8051 In-Circuit Emulator (ICE-51™)

The 8051 In-Circuit Emulator resides in the Intellec development system. The development system interfaces with the user's8051 system through an in-cable buffer box with the cable terminating in an 8051 pin-compatible plug. Together these replace the 8051 device in the system. With the emulator plug in place, the designer can exercise the system in real-time while collecting up to 255 instruction

AFN-01462A-10

7-10