RP-8212
The Parastream RP-8212 is a replacement part for the Intel 8212.
It is functionally equivalent to the 8212 with superior DC electrical specifications and superior AC electrical specifications in most regards.
The RP-8212 has the same pinout and footprint as the 8212, but is very slightly larger. See the datasheet for details before ordering.
Parastream also offers two cost-reduced variants, the RP-8212-IN and the RP-8212-OUT which will work in the vast majority of applications if properly chosen.
Neither variant supports CLR nor the service request flip-flop, as these features would require additional components and increase the cost.
The Parastream RP-8212-IN is designed to work in applications where the 8212 is hard-wired in input mode where pin 2 (MD) is connected to GND.
DS1 • DS2 enable the output buffers and drive INT through an inverter.
STB acts as the transparent latch clock.
MD and CLR are not connected.
The Parastream RP-8212-OUT is designed to work in applications where the 8212 is hard-wired in output mode where pin 2 (MD) is tied high.
The output buffers are always enabled.
DS1 • DS2 acts as the transparent latch clock and drive INT through an inverter.
STB, MD and CLR are not connected.
Choosing the Right Variant
If the application requires any of the following, the standard RP-8212 is required:
- The service request flip-flop, set by STB ↓, reset by DS1 • DS2 or CLR, and affecting INT.
- CLR setting the data latches to zero.
- MD is an active signal (is not tied high or low).
If MD is tied low and none of the above conditions are required, the RP-8212-IN is an option.
If MD is tied high and none of the above conditions are required, the RP-8212-OUT is an option.
Bare Boards
For the hobbyist who is proficient at 25 mil surface mount soldering, bare boards are available for the RP-8212 and the RP-8212-IN/OUT variant.
8212 and Related Parts
The 8212 has a 7400 series equivalent − the 74412. It is available in Schottky, FAST, and CMOS. The 74432 is the same functionality with inverting output buffers. The Schotty version (74S412) is equivalent to the 8212, and was only produced by Texas Instruments.
AMD
AMD produced the 8212 under the following aliases: Am3212, Am8212, Am54S412, and Am74S412. An application note was also published.
Fairchild
Fairchild produced the 74F412, and 74F432.
Intel
Intel designed and produced the 8212 (aka 3212). Also the industrial grade I8212 and the military grade M8212. The early datasheets showed a non-inverting buffer on the CLR pin as shown in this example. Later datasheets showed an OR gate on the CLR pin with the other input coming from the data latch clock inputs in an attempt to show the priority of the data latch clock over the clear. Unfortunately, it incorrectly implied that the data latch clock-qualified signal also affects the service request flip-flop reset, which it does not.
National
National Semiconductor produced the INS8212. It also produced the 74F412 and 74F432.
NEC
NEC produced the µPB8212.
OKI
OKI Semiconductor produced the only known CMOS version, the MSM82C12. Utsource has these parts for sale for cheap as of 2023.
Signetics
Signetics produced the 74F412 and 74F432.
Texas Instruments
TI designed and produced the 7400-series equivalent to the Intel 8212, the SN74S412.