Texas Instruments TP0320


Texas Instruments introduced the TMC0980 family of single-chip calculator circuits in June 1976 with the two scientific calculators SR-40/TI-30 and the counterpart Business Analyst for financial applications. Within two years Texas Instruments introduced with the TI-50, TI-53, and Business Analyst II calculators with a similar feature set in a much smaller housing and powered by two small button style alkaline batteries good for more than 1,000 hours of operation time. This tremendous progress was made possible by replacing the power-hungry LED Display with an LC-Display and switching the manufacturing process of the single-chip calculator circuit from a 9V metal gate PMOS process to a 3V metal gate CMOS process. The TP0320 family is based on the TMC0980 design, an extension of the TMS1000 Microcomputer family, but sports a larger data memory. The TP0320 chip includes 18,432 Bits Read-only Memory (ROM, 2k*9 Bits) and 832 Bits Read-access Memory (RAM, 12 Registers * 16 digits, 64 Bits Display), a 4-bit Arithmetic unit, a programmable PLA for segment decoding and both segment and digit multiplexing for a 9-digit LC-Display with up to 66 segments and 3 common scan lines.

The TP0310 chip developed at the same time as the TP0320 for the TI-1030 traces back to the TMC0920, while the next-generation TP0455 allows for a 12-digit LC-Display, timekeeping functionality with a 32.768 kHz crystal, and a 4-bit I/O bus for processor-to-processor communication inherited from the failed TP0485.  

Due to a flexible design concept with both programmable ROM and segment decoder some design variations appeared. 

Family Members and Applications

Type Calculator/Product Application Comments
TP0320/CD3201 Investment Analyst Financial ROM code CD3201
TP0320/CD3202 TI-30-II, TI-30 LCD, SR-40 LCD Scientific ROM code CD3202
TP0321 TI-50, Radio Shack EC-497 Scientific 2 Constant Memories
TP0322 Business Analyst II, TI-44, BA-III, Radio Shack EC-5100 Financial Statistical Functions
TP0323 TI-53 1st Gen., TI-53 2nd Gen. Scientific 32 Program Steps
TP0324 TI-35 Scientific Statistical Functions
TP0325 Business Card Financial Small housing, 28 keys
TP0326 TI-20, TI-38 Scientific Conversion Functions
TP0327 Sharp EL-503 Scientific 28 keys
TP0328 Jeppesen avstar 1st Gen., Jeppesen avstar 2nd Gen. Flight Computer Conversions and calculations



  Description Comments
Architecture Single-chip Calculator Scientific, Financial
Category Digit Processor 4-bit digits
Related TMC0980 PMOS, 7-segment LED-Display
ROM Size 18,432 Bits 2048 Words * 9 Bits
RAM Size 832 Bits 12 Registers * 16 digits
64 Bits Display Register
Outputs 3 Common, 22 Segments Integrated Common Scan Line and Segment Drivers
Inputs 5 Keyboard Segment to Keyboard Scan-Matrix

Technical Specifications

Item Min Typ Max Unit Comments
VDD   3.0   V   
VSS   0   V   
CK  250 350 450 kHz  Internal oscillator       


The TP0320 is manufactured in a tbd um metal gate CMOS process.

The die size of the TP0320 is approximately 220 mils * 220 mils / 5.6 mm * 5.6 mm.


The TP0320 uses either a 0.6 wide 28-pin DIP (Plastic Dual In-line Package with a 0.1 / 2.54 mm lead pitch)
or a 0.4 wide 28-pin SPDIP (Shrink Plastic Dual In-line Package with a 0.07 / 1.778 mm lead pitch).

Pin Configuration


Pin IO Function Pin IO Function
1   n.c. 28 O Segments FIN, SIGN, STAT
2 O LCD COM 1 27 O Segments E8, F8, E1
3 O LCD COM 2 26 O Segments D8, G8, A8
4 O LCD COM 3 25 O Segments DP8, C8, B8
5 IO Key row 6, D7, G7, A7 24 IO Key input 1, E7, F7, G1
6 IO Key row 5, E6, F6, F1 23 O Segments DP7, C7, B7
7 IO Key row 3, DP6, C6, B6 22 IO Key input 2, D6, G6, A6
8 IO Key row 4, D5, G5, A5 21 O Segments E5, F5, A1
9 IO Key row 1, E4, F4, B1 20 IO Key input 3, DP5, C5, B5
10 IO Key row 2, DP4, C4, B4 19 IO Key input 4, D4, G4, A4
11 IO Key row 7, D3, G3, A3 18 O Segments E3, F3, C1
12 O Segments E2, F2, D1 17 IO Key input 8, DP3, C3, B3
13 O Segments DP2, C2, B2 16 O Segments D2, G2, A2
14 VI Key row 8, VDD 15 V Negative Voltage VSS
The Segment drivers A-G and the Decimal point are connected to a display in the pictured way. 

Keyboard Scan-Matrix

The keyboards of all calculators based on the TP0320 family consist of an x/y-matrix connected to up to seven segment outputs with the top row ([ON] key) connected to VDD and the keymatrix inputs K1, K2, K3, K4, and K8. 

Example for the Business Analyst II with TP0322: 

  K1 K2 K3 K4 K8
Row 7 N %I PMT PV FV
Row 6 x<>y CST SEL MAR K
Row 5 SUM+ % X2 1/X :
Row 4 STO 7 8 0 *
Row 3 RCL 4 5 6 -
Row 2 SUM 1 2 3 +
Row 1 EXC 0 . +/- =


Calculators based on the TP0320 make use of a 9-digit LCD-display with 3 COM (common scan) lines. 

horizontal rule

If you have additions to the above datasheet please email:

Sean Riddle and Joerg Woerner, January 10, 2021. No reprints without written permission.