{{tag>collection_FelineFriendly vendor_bosch year_1990 foundry_unknown tech_unknown}}

====== Description ======
This part was taken from a Motronic M1.7 engine control unit (ECU), which was used on the M42 engine of the BMW E30 318iS. While this chip was likely used on a number of ECUs, the specific one in this case had Bosch PN 0 261 200 175.

Functionally, this chip serves a variety of purposes, with the best high-level description stating that it is a programmable peripheral interface (PPI). It bears some similarity to standard devices such as the 8155 and 8255, but it is clearly a custom part based on the number of IO's. Some of the functions it provides are:

- Latching of the low-byte address (from the data lines) for external ROM and RAM accesses

- Some internal digital logic which takes the A13-15 inputs and outputs enable/disable signals on other IO pins for other ICs

- Provides additional latching IO pins

- Provides additional IO pins

- Provides additional input-only pins

- Interfaces with the external L-Line diagnostic interface which is used by various code scanner tools to initiate communication on the faster K-Line interface

There were other versions of this part used across the family of Motronic 1.x ECUs. Package markings indicate that Harris Semiconductor also made a number of these chips. Internal differences are unknown, but the functional implementation was always the same. Communication with Intersil (formerly Harris) about these parts indicates that there is no surviving internal documentation on these parts. Bosch and Philips did not respond to any inquiries about their versions of the parts.
====== Package ======
Label (top):

<code>
[Philips Logo] [Bosch Logo]
30074 (Bosch internal PN)
9010
030972
CC151 V1
Dt
</code>

{{:felinefriendly:bosch:b30074:s702_pkg.jpg?400|}}

{{:felinefriendly:bosch:b30074:s702_pkgrf2.jpg?400|}}

====== Die ======

<code>
Decap Steps:
Grind bottom side of package with 60 & 240 grit sandpaper until die is exposed
Grind top side of package until ~0.5mm remains above die
Use precision diagonal cutters to fracture remaining packaging off of die
Use CA glue to bond die to glass slide (the "glob top" material is still present at this stage)
Use optical swabs and IPA to scrub "glob top" coating off
Rinse with IPA
Clean with fine polishing cloth and IPA
Polish with fine polishing cloth and 0.5 micron polycrystalline diamond suspension

Capture Details:
Imaging device: Keyence VHX-2000
Magnification: 500X

Markings:
V733V1
[Bosch Logo]
Bosch
©1986
©1987
CC151
</code>

Imaged using normal / center lighting:

{{:felinefriendly:bosch:b30074:s702_die_normallight_500x_small.jpg?400|}}

//Note: This is a ~16X downsampled version of the original image. A full resolution version (55MB) can be provided. On the to-do list…//

Imaged using edge lighting, for enhanced shadow contrast: 

{{:felinefriendly:bosch:b30074:s702_die_edgelight_500x_small.jpg?400|}}

//Note: This is a ~16X downsampled version of the original image. A full resolution version (85MB) can be provided. On the to-do list…//

====== Die - Original Attempt ======

<code>
Decap Steps:
Selective crushing with pliers and bench vise

Capture Details:
Imaging device: Keyence VHX-2000
Magnification: 300X

Markings:
V733V1
[Bosch Logo]
Bosch
©1986
©1987
CC151
</code>

The die had a clear conformal coating covering it, which was left in place for initial imaging.

{{:felinefriendly:bosch:b30074:s702_die_300x.jpg?400|}}

Subsequent efforts to remove the coating destroyed the die, so no additional images were taken of this sample.