The 4-bit Eight Bit Processor – AMI S2000 and Iskra EMZ1001
Iskra EMZ100E
Again in 1975 the College of Electrical Engineering of the College of Ljubljana (now the Capital of Slovenia, however again then, a metropolis in Yugoslavia) started work with Iskra and AMI to develop an indigenously produced processor. Iskra (which suggests ‘Spark’ in Slovenian) started in 1946 and by this time was the most important electronics/telecom firm in Yugoslavia. If it had electrons flowing via it, Iskra doubtless had one thing to do with it. AMI was an American Semiconductor firm greatest identified on the time as a contract fab and second supply for a lot of different firms. On the time they have been a fairly large 2nd supply for Motorola, making 6800 processors and peripherals.
The purpose was to co-develop a primary management oriented processor, one thing that would run primary machines and industrial automation kind stuff, toaster oven, video games, and many others. It wasn’t meant to be a normal objective pc kind processor cranking out spreadsheet system outcomes. In lots of circumstances the design was to fill the identical position because the Nationwide Semiconductor COPS400 line. Iskra hoped to finally manufacture the processors in Yugoslovia with expertise and tools from AMI, however Yugoslavia and the US have been in a little bit of a bizarre spot within the 1970’s so getting export licenses for fab tools by no means occurred. Yugoslavia was moderately impartial of the Soviet Union (because of the Stalin-Tito rift) which afforded them entry to the US that different communist nations of the time didn’t have, however they have been nonetheless nominally communist. One has to marvel how exhausting AMI tried to get such licenses although.
The processor they developed was referred to as the S2000 within the West, and in Yugoslavia, the Iskra EMZ1001. These processors have been made on an AMI NMOS course of (most certainly 6 micron) with 1200 transistors. AMI would fab the wafers and ship them to Iskra for last take a look at/meeting.
The EMZ1001/S2000 has been referred to as each a 4-bit and an 8-bit processor. It’s because it interfaces to the skin world with an 8-bit databus (and a 13-bit deal with bus) however has a 4-bit ALU at its core. Internally it has each a 4-bit bus and an 8-bit bus, and may carry out 8-bit arithmetic, simply 4-bits at a time. This in fact leads to a efficiency hit, however with a 4.5microsecond cycle time (225KHz) it wasn’t meant to be a excessive velocity chip. It consists of logic on chip to deal with timers, and second counting (even a EUR instruction to modify the time base from the 60Hz US customary, to the 50Hz Euro customary) in addition to interfaces for buttons, and Capacitive Contact plates and LEDs (S2000) or Vacuum Fluorescent Drivers (S2000A). It was designed to run on a single 9V provide, making it viable to make use of off of a 9V battery.
AMI S2000 Dev System (the S6800 Devsystem may be used )
The S2000/EMZ1001 instruction set comprises 51 directions. all of that are single byte. 49 of those are single cycle directions. The processor comprises a stack making subroutines and interrupts (on the 2200/2400) simple to deal with. 1kx8 of onboard ROM is included (as much as 8K whole might be addressed) in addition to 256 bits of RAM (16x4x4) (which can be utilized for registers, in addition to addresses reminiscence).
A number of subversions of the processor have been made with completely different options and a few added directions to deal with ADC features. The S2200/2400 add an 8-bit ADC and extra RAM and ROM (and have 8 further directions).
| S2000/ EMZ1001 |
S2000A/ EMZ1001A |
S2150 | S2150A | S2200 | S2200A | S2400 | S2400A | |
| ROM (Bytes) | 1K | 1K | 1.5K | 1.5K | 2K | 2K | 4K | 4K |
| RAM (x4) | 64 | 64 | 80 | 80 | 128 | 128 | 128 | 128 |
| 8-bit ADC | – | – | – | – | Y | Y | Y | Y |
| Timer | 50/60Hz | 50/60Hz | 50/60Hz | 50/60Hz | 8-bit PRG | 8-bit PRG | 8-bit PRG | 8-bit PRG |
| Interrupts | – | – | – | – | 3 | 3 | 3 | 3 |
| Energy Fail Detect | – | 9 | – | – | Y | Y | Y | Y |
| Excessive Voltage Outputs | – | Y | – | Y | – | Y | – | Y |
| Contact Management Inputs | Y | Y | Y | Y | Y | Y | Y | Y |
| Stack Depth | 3 | 3 | 3 | 3 | 5 | 5 | 5 | 5 |
| # of FLags | 2 | 2 | 2 | 2 | 262 | 262 | 262 | 262 |
| PWR Down RAM Choice | – | – | Y | Y | Y | Y | Y | Y |
| DAC Choice | Y | Y | Y | Y | Y | Y | Y | Y |
There was a CMOS model as effectively, the S2210, for decrease energy functions.
AMI Emblem – There was a number of die revisions that AMI made.
As Iskra was receiving wafers from AMI and was testing them inhouse, they have been in a position to make a number of temperature scores.
EMZ1001B 0-55C
EMZ1001C 0-70C
EMZ1001E 0-85C
EMZ1001KCP -40-85C (Industrial/Army Functions)
By the point Iskra was in a position to start testing/packaging these, it was 1977-78, and the design was a bit underwhelming for the market. Nonetheless it discovered pretty broad use in Yugoslavia. The Western equivalents although, are virtually by no means seen making the Iskra model maybe extra frequent, and broadly used.