Basic 8031 µP Development PCB

Intel introduced the 8051 (MCS-51) 8-bit microcontroller in 1980. It has become the industry standard for embedded control made by many independant manufacturers in a wide range of variants. The 8031 µP and 8032 µP are romless 8051 µP variants, 18 of the 32 I/O pins are used for external memory access. The 8032 µP offers 256 instead of 128 byte on-chip RAM and has an extra 16 bit timer/counter.

The basic 8031 µP pcb is a development board with no peripherals except for the external memory. Depending on using an 8031 µP or 8032 µP its functionality offers:

8-bit CPU with boolean processor, 64K code and 64K data space memory addressing
128 (8031 µP) or 256 (8032 µP) bytes on-chip RAM
2 (8031 µP) or 3 (8032 µP) 16-bit timers/counters
programmable full-duplex serial 5-pin or 10-pin port (baud rate could be provided by one of the timers).
8K or 32K external RAM
8K, 16K or 32K external EPROM
8K, 16K or 32K external EEPROM
40-pin peripheral I/O extension bus with 8 chip select lines for I/O addressing
14-pin I/O connector for 9 (32K EEPROM present) or 10 general purpose I/O pins (J1 1-2 closed)

8031 µP schematics and layouts

The number of top side connections are limited; it are a couple of power connections and about 22 other wires. The basic 8031 DIP40 development board could be very well made as a single sided board. Use the top wire layout to determine the remaining top wire connections to bottom wire a single sided board. View the PCB etching page to produce the PCB.

The number of top side connections are limited; it are a couple of power connections and about 28 other wires. The basic 8031 PLCC44 development board could be very well made as a single sided board. Use the top wire layout to determine the remaining top wire connections to bottom wire a single sided board. View the PCB etching page to produce the PCB.

The 10-pin serial interface is compatible with the IF-Module serial interface system as offered by Elektronikladen and TaskIt. Alternatives are offered here.

Memory map, CS = code space, DS = data space
DS+CS: CS: DS: DS: DS:	RAM EPROM EEPROM EEPROM I/O	32K - 64K 0 - 32K 16K - 32K, BANK0, P3.5 = 0, J1 2-3 closed 16K - 32K, BANK1, P3.5 = 1, J1 2-3 closed 0 - 16K

Bill of Materials
X1 IC1 IC2 IC3 IC4 IC5 IC6 IC7 IC8 R1 R2 R3, R4, R5 C1, C2 C3 C4 C5, C6, C7, C8, C9, C10, C11, C12 SW1 J1 J2 J3 J4 J5 J6 J7 J8 F1	X-tal 11.0592 MHz 80C31 or 80C32, DIP40 or PLCC44 package 8K - 62C64 or 32K - 62C256 RAM 8K - 27C64, 16K - 27C128 EPROM (J6 1-2 closed) or 32K - 27C256 EPROM (J6 2-3 closed) 8K - 28C64, 16K - 28C128 EEPROM or 32K - 28C256 EEPROM (J1 2-3 closed) 74HCT00 4 x NAND 74HCT32 4 x OR 74HCT573 D-latch 74HCT138 3/8 demultiplexer 100kΩ 220R 10k resistor network 9-pin 8R + 1 common 22nF 22µF radial 10µF radial 100nF reset switch 3-pin 32K EEPROM selection connector 2.54mm 5-pin serial connector 2.54mm 40-pin extension bus connector 2.54mm 14-pin general purpose I/O connector 2.54mm 10-pin serial connector 2.54mm (same TX/RX as 5-pin) 3-pin EPROM selection jumper 2.54mm 5V power connector reset connector fuse 500mA	1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 3x 2x 1x 1x 8x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x

Basic 8031 DIP40 component layout

8031 µP DIP40 component layout 131mm x 70mm. R4 and R5 are not required when the 8031 µP P1 and P3 ports have internal pull-up resistors.

Basic 8031 PLCC44 component layout

8031 µP PLCC44 component layout 131mm x 70mm. R4 and R5 are not required when the 8031 µP P1 and P3 ports have internal pull-up resistors.

Basic 80C535 µP Development PCB

The basic 80C535 µP pcb (8031 µP compatible) is a development board with no peripherals except for the external memory. Its functionality offers:

8-bit CPU with boolean processor, 64K code and 64K data space memory addressing
256 bytes on-chip RAM
three 16-bit timers/counters
16-bit reload, compare, capture capability
16-bit watchdog timer
12 interrupt sources (7 external, 5 internal), 4 priority levels
stack depth up to 256 byte
1 µs instruction cycle at 12-MHz operation
4 µs multiply and divide
one input port for digital input or
A/D converter, 8 multiplexed analog inputs, programmable reference voltages
programmable full-duplex serial 5-pin or 10-pin port (baud rate could be provided by one of the timers).
8K or 32K external RAM
8K, 16K or 32K external EPROM
8K, 16K or 32K external EEPROM
40-pin peripheral I/O extension bus with 8 chip select lines for I/O addressing
30-pin I/O extension bus for 16 general purpose I/O pins and 8 multiplexed analog inputs or 8 digital inputs
14-pin I/O connector for 9 (32K EEPROM present) or 10 general purpose I/O pins (J1 1-2 closed)

80C535 µP schematics and layouts

80C535 µP PLCC68 schematics

The 10-pin serial interface is compatible with the IF-Module serial interface system as offered by Elektronikladen and TaskIt. Alternatives are offered here.

Memory map, CS = code space, DS = data space
DS+CS: CS: DS: DS: DS:	RAM EPROM EEPROM EEPROM I/O	32K - 64K 0 - 32K 16K - 32K, BANK0, P3.5 = 0, J1 2-3 closed 16K - 32K, BANK1, P3.5 = 1, J1 2-3 closed 0 - 16K

Bill of Materials
X1 IC1 IC2 IC3 IC4 IC5 IC6 IC7 IC8 R1 R2 R3 C1, C2 C3 C4 C5, C6, C7, C8, C9, C10, C11, C12 SW1 J1 J2 J3 J4 J5 J6 J7 J8 J9 F1	X-tal 16 MHz SAB80C535 PLCC68 package 8K - 62C64 or 32K - 62C256 RAM 8K - 27C64, 16K - 27C128 EPROM (J6 1-2 closed) or 32K - 27C256 EPROM (J6 2-3 closed) 8K - 28C64, 16K - 28C128 EEPROM or 32K - 28C256 EEPROM (J1 2-3 closed) 74HCT00 4 x NAND 74HCT32 4 x OR 74HCT573 D-latch 74HCT138 3/8 demultiplexer 100kΩ 220R 10k resistor network 9-pin 8R + 1 common 22nF 22µF radial 10µF radial 100nF reset switch 3-pin 32K EEPROM selection connector 2.54mm 5-pin serial connector 2.54mm 40-pin extension bus connector 2.54mm 14-pin general purpose I/O connector 2.54mm 10-pin serial connector 2.54mm (same TX/RX as 5-pin) 3-pin EPROM selection jumper 2.54mm 5V power connector reset connector 30-pin general purpose I/O connector 2.54mm fuse 500mA	1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 2x 1x 1x 8x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x