MASK ROM

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Part	Manufacturer	Memory IC Type	Temperature Grade	No. of Terminals	Package Code	Package Shape	Package Body Material	Surface Mount	No. of Functions	Technology	Terminal Form	Parallel or Serial	Operating Mode	Maximum Supply Current	No. of Words	Nominal Supply Voltage / Vsup (V)	Power Supplies (V)	Memory Width	Package Style (Meter)	Package Equivalence Code	Alternate Memory Width	Sub-Category	Terminal Pitch	Maximum Operating Temperature	Output Characteristics	Organization	No. of Words Code	Minimum Operating Temperature	Terminal Position	JESD-30 Code	Maximum Supply Voltage (Vsup)	Maximum Seated Height	Width	Qualification	Memory Density	Minimum Supply Voltage (Vsup)	Maximum Time At Peak Reflow Temperature (s)	Peak Reflow Temperature (C)	Maximum Standby Current	Length	Maximum Access Time
TMS47C1024FM25	Texas Instruments
TMS47C512FM30	Texas Instruments
5962-01-064-9584	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	PLASTIC/EPOXY	NO		TTL	THROUGH-HOLE			130 mA	256 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		256X4	256	0 Cel	DUAL	R-PDIP-T16				Not Qualified	1024 bit		NOT SPECIFIED	NOT SPECIFIED			60 ns
5962-01-052-9505	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			130 mA	256 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		256X4	256	0 Cel	DUAL	R-XDIP-T16				Not Qualified	1024 bit		NOT SPECIFIED	NOT SPECIFIED			60 ns
5962-01-004-8180	Texas Instruments	MASK ROM	MILITARY	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			80 mA	32 words	5	5	8	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	125 Cel		32X8	32	-55 Cel	DUAL	R-XDIP-T16				Not Qualified			NOT SPECIFIED	NOT SPECIFIED			45 ns
SN54S371J	Texas Instruments	MASK ROM	MILITARY	20	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			155 mA	256 words	5	5	8	IN-LINE	DIP20,.3		MASK ROMs	2.54 mm	125 Cel		256X8	256	-55 Cel	DUAL	R-XDIP-T20				Not Qualified	2048 bit		NOT SPECIFIED	NOT SPECIFIED			95 ns
TMS47C256-15FM	Texas Instruments
TMS47256-25FML	Texas Instruments	MASK ROM	COMMERCIAL	32	QCCJ	RECTANGULAR	PLASTIC/EPOXY	YES	1	NMOS	J BEND	PARALLEL	ASYNCHRONOUS	60 mA	32768 words	5	5	8	CHIP CARRIER	LDCC32,.5X.6		MASK ROMs	1.27 mm	70 Cel	3-STATE	32KX8	32K	0 Cel	QUAD	R-PQCC-J32	5.5 V	3.56 mm	11.43 mm	Not Qualified	262144 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		13.97 mm	250 ns
TMS47C256-20NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	CMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	50 mA	32768 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	32KX8	32K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	262144 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	200 ns
TMS47C256-25NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	CMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	50 mA	32768 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	32KX8	32K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	262144 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	250 ns
5962-01-050-6920	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			130 mA	256 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		256X4	256	0 Cel	DUAL	R-XDIP-T16				Not Qualified	1024 bit		NOT SPECIFIED	NOT SPECIFIED			60 ns
5962-01-050-6934	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			130 mA	256 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		256X4	256	0 Cel	DUAL	R-XDIP-T16				Not Qualified	1024 bit		NOT SPECIFIED	NOT SPECIFIED			60 ns
SN54S370J	Texas Instruments	MASK ROM	MILITARY	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			155 mA	512 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	125 Cel		512X4	512	-55 Cel	DUAL	R-XDIP-T16				Not Qualified	2048 bit		NOT SPECIFIED	NOT SPECIFIED			95 ns
5962-01-075-5700	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	PLASTIC/EPOXY	NO		TTL	THROUGH-HOLE			80 mA	32 words	5	5	8	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		32X8	32	0 Cel	DUAL	R-PDIP-T16				Not Qualified			NOT SPECIFIED	NOT SPECIFIED			45 ns
TMS47C256-25FML	Texas Instruments	MASK ROM	COMMERCIAL	32	QCCJ	RECTANGULAR	PLASTIC/EPOXY	YES	1	CMOS	J BEND	PARALLEL	ASYNCHRONOUS	50 mA	32768 words	5	5	8	CHIP CARRIER	LDCC32,.5X.6		MASK ROMs	1.27 mm	70 Cel	3-STATE	32KX8	32K	0 Cel	QUAD	R-PQCC-J32	5.5 V	3.56 mm	11.43 mm	Not Qualified	262144 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		13.97 mm	250 ns
TMS2364-15NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	NMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	60 mA	8192 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	8KX8	8K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	65536 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	150 ns
5962-01-028-6972	Texas Instruments	MASK ROM	MILITARY	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			80 mA	32 words	5	5	8	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	125 Cel		32X8	32	-55 Cel	DUAL	R-XDIP-T16				Not Qualified			NOT SPECIFIED	NOT SPECIFIED			45 ns
TMS47C1024-20FML	Texas Instruments	MASK ROM	COMMERCIAL	32	QCCJ	RECTANGULAR	PLASTIC/EPOXY	YES	1	CMOS	J BEND	PARALLEL	ASYNCHRONOUS		131072 words	5	5	8	CHIP CARRIER	LDCC32,.5X.6		MASK ROMs	1.27 mm	70 Cel	3-STATE	128KX8	128K	0 Cel	QUAD	R-PQCC-J32	5.5 V	3.56 mm	11.43 mm	Not Qualified	1048576 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		13.97 mm	200 ns
5962-01-028-6968	Texas Instruments	MASK ROM	MILITARY	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			80 mA	32 words	5	5	8	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	125 Cel		32X8	32	-55 Cel	DUAL	R-XDIP-T16				Not Qualified			NOT SPECIFIED	NOT SPECIFIED			45 ns
TMS47C1024-20NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	CMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS		131072 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	128KX8	128K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	1048576 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	200 ns
TMS2332-25NL	Texas Instruments	MASK ROM	COMMERCIAL	24	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	NMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	60 mA	4096 words	5	5	8	IN-LINE	DIP24,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	4KX8	4K	0 Cel	DUAL	R-PDIP-T24	5.5 V	5.08 mm	15.24 mm	Not Qualified	32768 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		31.75 mm	250 ns
TMS47128-20NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	NMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	60 mA	16384 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	16KX8	16K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	131072 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	200 ns
TMS47C1024FM30	Texas Instruments
5962-01-058-0625	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	PLASTIC/EPOXY	NO		TTL	THROUGH-HOLE			130 mA	256 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		256X4	256	0 Cel	DUAL	R-PDIP-T16				Not Qualified	1024 bit		NOT SPECIFIED	NOT SPECIFIED			60 ns
TMS47C512-30NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	CMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS		65536 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	64KX8	64K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	524288 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	300 ns
TMS4764-20NL	Texas Instruments	MASK ROM	COMMERCIAL	24	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	NMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	60 mA	8192 words	5	5	8	IN-LINE	DIP24,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	8KX8	8K	0 Cel	DUAL	R-PDIP-T24	5.5 V	5.08 mm	15.24 mm	Not Qualified	65536 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		31.75 mm	200 ns
TMS47C256-15NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	CMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	50 mA	32768 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	32KX8	32K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	262144 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	150 ns
TMS47256-20NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	NMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	60 mA	32768 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	32KX8	32K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	262144 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	200 ns
TMS47C512-20FML	Texas Instruments	MASK ROM	COMMERCIAL	32	QCCJ	RECTANGULAR	PLASTIC/EPOXY	YES	1	CMOS	J BEND	PARALLEL	ASYNCHRONOUS		65536 words	5	5	8	CHIP CARRIER	LDCC32,.5X.6		MASK ROMs	1.27 mm	70 Cel	3-STATE	64KX8	64K	0 Cel	QUAD	R-PQCC-J32	5.5 V	3.56 mm	11.43 mm	Not Qualified	524288 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		13.97 mm	200 ns
TMS47C512-20NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	CMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS		65536 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	64KX8	64K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	524288 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	200 ns
TMS47C512-25NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	CMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS		65536 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	64KX8	64K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	524288 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	250 ns
SN74S371N	Texas Instruments	MASK ROM	COMMERCIAL	20	DIP	RECTANGULAR	PLASTIC/EPOXY	NO		TTL	THROUGH-HOLE			155 mA	256 words	5	5	8	IN-LINE	DIP20,.3		MASK ROMs	2.54 mm	70 Cel		256X8	256	0 Cel	DUAL	R-PDIP-T20				Not Qualified	2048 bit		NOT SPECIFIED	NOT SPECIFIED			70 ns
SN74S370N	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	PLASTIC/EPOXY	NO		TTL	THROUGH-HOLE			155 mA	512 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		512X4	512	0 Cel	DUAL	R-PDIP-T16				Not Qualified	2048 bit		NOT SPECIFIED	NOT SPECIFIED			70 ns
TSP60C20N	Texas Instruments	MASK ROM	OTHER	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO		CMOS	THROUGH-HOLE			1 mA	16384 words			16	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	80 Cel		16KX16	16K	-40 Cel	DUAL	R-PDIP-T28				Not Qualified	262144 bit				.0002 Amp
TMS47C1024-25FML	Texas Instruments	MASK ROM	COMMERCIAL	32	QCCJ	RECTANGULAR	PLASTIC/EPOXY	YES	1	CMOS	J BEND	PARALLEL	ASYNCHRONOUS		131072 words	5	5	8	CHIP CARRIER	LDCC32,.5X.6		MASK ROMs	1.27 mm	70 Cel	3-STATE	128KX8	128K	0 Cel	QUAD	R-PQCC-J32	5.5 V	3.56 mm	11.43 mm	Not Qualified	1048576 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		13.97 mm	250 ns
TMS47C256-15N	Texas Instruments
5962-01-052-9504	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			130 mA	256 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		256X4	256	0 Cel	DUAL	R-XDIP-T16				Not Qualified	1024 bit		NOT SPECIFIED	NOT SPECIFIED			60 ns
5962-01-052-9506	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			130 mA	256 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		256X4	256	0 Cel	DUAL	R-XDIP-T16				Not Qualified	1024 bit		NOT SPECIFIED	NOT SPECIFIED			60 ns
TMS47128-35NL	Texas Instruments	MASK ROM	COMMERCIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	NMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	60 mA	16384 words	5	5	8	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	16KX8	16K	0 Cel	DUAL	R-PDIP-T28	5.5 V	5.08 mm	15.24 mm	Not Qualified	131072 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		36.32 mm	350 ns
TMS47C1024-30FML	Texas Instruments	MASK ROM	COMMERCIAL	32	QCCJ	RECTANGULAR	PLASTIC/EPOXY	YES	1	CMOS	J BEND	PARALLEL	ASYNCHRONOUS		131072 words	5	5	8	CHIP CARRIER	LDCC32,.5X.6		MASK ROMs	1.27 mm	70 Cel	3-STATE	128KX8	128K	0 Cel	QUAD	R-PQCC-J32	5.5 V	3.56 mm	11.43 mm	Not Qualified	1048576 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		13.97 mm	300 ns
5962-01-028-6971	Texas Instruments	MASK ROM	MILITARY	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			80 mA	32 words	5	5	8	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	125 Cel		32X8	32	-55 Cel	DUAL	R-XDIP-T16				Not Qualified			NOT SPECIFIED	NOT SPECIFIED			45 ns
TMS4800NL	Texas Instruments	MASK ROM	COMMERCIAL	24	DIP	RECTANGULAR	PLASTIC/EPOXY	NO		MOS	THROUGH-HOLE			40 mA	2048 words			8	IN-LINE	DIP24,.6	4	MASK ROMs	2.54 mm	70 Cel		2KX8	2K	0 Cel	DUAL	R-PDIP-T24				Not Qualified	16384 bit						700 ns
5962-01-050-6919	Texas Instruments	MASK ROM	COMMERCIAL	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			130 mA	256 words	5	5	4	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	70 Cel		256X4	256	0 Cel	DUAL	R-XDIP-T16				Not Qualified	1024 bit		NOT SPECIFIED	NOT SPECIFIED			60 ns
TMS4732-20NL	Texas Instruments	MASK ROM	COMMERCIAL	24	DIP	RECTANGULAR	PLASTIC/EPOXY	NO	1	NMOS	THROUGH-HOLE	PARALLEL	ASYNCHRONOUS	60 mA	4096 words	5	5	8	IN-LINE	DIP24,.6		MASK ROMs	2.54 mm	70 Cel	3-STATE	4KX8	4K	0 Cel	DUAL	R-PDIP-T24	5.5 V	5.08 mm	15.24 mm	Not Qualified	32768 bit	4.5 V	NOT SPECIFIED	NOT SPECIFIED		31.75 mm	200 ns
TMS47C1024N30	Texas Instruments
TMS4800JL	Texas Instruments	MASK ROM	COMMERCIAL	24	DIP	RECTANGULAR	CERAMIC	NO		MOS	THROUGH-HOLE			40 mA	2048 words			8	IN-LINE	DIP24,.6	4	MASK ROMs	2.54 mm	70 Cel		2KX8	2K	0 Cel	DUAL	R-XDIP-T24				Not Qualified	16384 bit						700 ns
5962-01-028-6970	Texas Instruments	MASK ROM	MILITARY	16	DIP	RECTANGULAR	CERAMIC	NO		TTL	THROUGH-HOLE			80 mA	32 words	5	5	8	IN-LINE	DIP16,.3		MASK ROMs	2.54 mm	125 Cel		32X8	32	-55 Cel	DUAL	R-XDIP-T16				Not Qualified			NOT SPECIFIED	NOT SPECIFIED			45 ns
TSP60C81N	Texas Instruments	MASK ROM	INDUSTRIAL	28	DIP	RECTANGULAR	PLASTIC/EPOXY	NO		CMOS	THROUGH-HOLE			.3 mA	65536 words	5	5	16	IN-LINE	DIP28,.6		MASK ROMs	2.54 mm	85 Cel		64KX16	64K	-40 Cel	DUAL	R-PDIP-T28				Not Qualified	1048576 bit				.0001 Amp

MASK ROM

Mask ROM, or Read-Only Memory, is a type of non-volatile computer memory that is programmed during the manufacturing process. Mask ROM is designed to permanently store data and cannot be reprogrammed after it has been manufactured.

Mask ROM is created by a process known as photolithography. This process involves using a mask, or template, to expose specific areas of a silicon wafer to ultraviolet light. The areas that are exposed to the light are then etched away, leaving behind the patterns that make up the memory cells. Once the memory cells have been created, they are permanently programmed with the data that they will store.

Mask ROM is commonly used in devices that require permanent storage of data, such as game consoles, calculators, and other electronic devices. Because the data is permanently programmed during manufacturing, mask ROM provides a reliable and secure way to store critical data, such as system settings, firmware, and other important information.

One of the advantages of using mask ROM is that it is a cost-effective way to produce large quantities of memory. Because the data is programmed during the manufacturing process, the cost per unit is relatively low compared to other types of non-volatile memory, such as EEPROM or flash memory.