TDA936X データシートの表示（PDF） - Philips Electronics

部品番号

コンポーネント説明

メーカー

TDA936X

TV signal processor-Teletext decoder with embedded µ-Controller

Philips Electronics 

Philips Semiconductors

TV signal processor-Teletext decoder with

embedded µ-Controller

Preliminary specification

TDA 935X/6X/8X series

Security Bits - Program and Verify

TDA935X/6X/8X devices have three sets of security bits, one set for each of the three One Time Programmable

memories, i.e. Program ROM, Character ROM and Packet 26 ROM. The security bits are used to prevent the

ROM from being overwritten once programmed, and also the contents being verified once programmed. The

security bits are one-time programmable and cannot be erased.

The TDA935X/6X/8X memory and security bits are structured as shown in Figure 6. The security bits are set as

shown in Figure 7 for production programmed devices and are set as shown in Figure 8 for production blank

devices.

handbook, full pagewidthMEMORY

PROGRAM ROM

UUseSrERRoRmOM

(1(21288KKxx 812-B-BiItT))

CHARACTER ROM

UUsSeEr RRRomOM

(9(1K28xK1x21-B2-iBt)IT)

PACKET 26 ROM

UUsSeEr RRRoOmM

((412K8Kx x8-1B2-iBt)IT)

SECURITY BITS INTERACTION

USER ROM PROGRAMMING

VERIFY

(ENABLE/DISABLE)

(ENABLE/DISABLE)

USER ROM PROGRAMMING

VERIFY

(ENABLE/DISABLE)

(ENABLE/DISABLE)

USER ROM PROGRAMMING

VERIFY

(ENABLE/DISABLE)

(ENABLE/DISABLE)

MBK953

Figure 6 Memory and security bit structures

handbook, full pagewidthMEMORY

PROGRAM ROM

CHARACTER ROM

PACKET 26 ROM

SECURITY BITS SET

USER ROM PROGRAMMING

VERIFY

(ENABLE/DISABLE)

(ENABLE/DISABLE)

DISABLED

ENABLED

DISABLED

ENABLED

DISABLED

ENABLED

MBK954

1999 Sep 28

Figure 7 Security bits for production devices

13

Share Link: