TMS320E25

SPRS010B Ð MAY 1987 Ð REVISED NOVEMBER 1990

ADVANCE INFORMATION

 

 

 

 

 

 

 

Program

 

 

 

 

 

 

A12-A0

 

 

 

 

 

Verify

VIH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Address Stable

 

 

Address N + 1

 

 

 

 

 

 

 

 

 

 

 

 

 

VIL

Q8-Q1

 

 

 

 

 

 

 

VIH/VOH

Data In Stable

 

HI-Z

 

Data Out Valid

 

 

 

 

 

 

 

 

 

 

 

 

 

VIL/VOL

 

 

 

 

 

 

 

 

 

 

 

 

VPP

 

 

 

 

 

 

 

VPP

 

 

 

 

 

 

 

 

VCC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VCC

 

 

 

 

 

 

 

VCC + 1

 

 

 

 

 

 

 

 

VCC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VIH

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VIL

 

 

 

 

 

 

 

 

 

 

 

 

 

VIH

 

PGM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VIL

 

 

 

 

 

 

 

 

 

 

 

 

 

VIH

 

 

G

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VIL

Figure 11. Fast Programming Timing

program inhibit

Programming may be inhibited by maintaining a high level input on the E pin or PGM pin.

read

The EPROM contents may be read independent of the programming cycle, provided the RBIT (ROM protect bit) has not been programmed. The read is accomplished by setting E to zero and pulsing G low. The contents of the EPROM location selected by the value on the address inputs appear on Q8-Q1.

output disable

During the EPROM programming process, the EPROM data outputs may be disabled, if desired, by establishing the output disable state. This state is selected by setting the G and PGM pins high. While output disable is selected, Q8-Q1 are placed in the high-impedance state.

ROM protection and verification

This section describes the code protection feature included in the EPROM cell, which protects code against copyright violations. Table 6 shows the programming levels required for protecting and verifying the EPROM. The paragraphs following the table describe the protect and verify functions.

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Texas Instruments TMS320 specifications Read, Output disable, ROM protection and verification