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P80C32 数据表(PDF) 49 Page - NXP Semiconductors |
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P80C32 数据表(HTML) 49 Page - NXP Semiconductors |
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49 / 62 page ![]() Philips Semiconductors Product data P80C3xX2; P80C5xX2; P87C5xX2 80C51 8-bit microcontroller family 4K/8K/16K/32K ROM/OTP, low voltage (2.7 to 5.5 V), low power, high speed (30/33 MHz) 2003 Jan 24 49 EPROM CHARACTERISTICS The OTP devices described in this data sheet can be programmed by using a modified Improved Quick-Pulse Programming ™ algorithm. It differs from older methods in the value used for VPP (programming supply voltage) and in the width and number of the ALE/PROG pulses. The family contains two signature bytes that can be read and used by an EPROM programming system to identify the device. The signature bytes identify the device as being manufactured by Philips. Table 9 shows the logic levels for reading the signature byte, and for programming the program memory, the encryption table, and the security bits. The circuit configuration and waveforms for quick-pulse programming are shown in Figures 40 and 41. Figure 42 shows the circuit configuration for normal program memory verification. Quick-Pulse Programming The setup for microcontroller quick-pulse programming is shown in Figure 40. Note that the device is running with a 4 to 6 MHz oscillator. The reason the oscillator needs to be running is that the device is executing internal address and program data transfers. The address of the EPROM location to be programmed is applied to ports 1 and 2, as shown in Figure 40. The code byte to be programmed into that location is applied to port 0. RST, PSEN and pins of ports 2 and 3 specified in Table 9 are held at the ‘Program Code Data’ levels indicated in Table 9. The ALE/PROG is pulsed low 5 times as shown in Figure 41. To program the encryption table, repeat the 5 pulse programming sequence for addresses 0 through 1FH, using the ‘Pgm Encryption Table’ levels. Do not forget that after the encryption table is programmed, verification cycles will produce only encrypted data. To program the security bits, repeat the 5 pulse programming sequence using the ‘Pgm Security Bit’ levels. After one security bit is programmed, further programming of the code memory and encryption table is disabled. However, the other security bits can still be programmed. Note that the EA/VPP pin must not be allowed to go above the maximum specified VPP level for any amount of time. Even a narrow glitch above that voltage can cause permanent damage to the device. The VPP source should be well regulated and free of glitches and overshoot. Program Verification If security bits 2 and 3 have not been programmed, the on-chip program memory can be read out for program verification. The address of the program memory locations to be read is applied to ports 1 and 2 as shown in Figure 42. The other pins are held at the ‘Verify Code Data’ levels indicated in Table 9. The contents of the address location will be emitted on port 0. External pull-ups are required on port 0 for this operation. If the 64 byte encryption table has been programmed, the data presented at port 0 will be the exclusive NOR of the program byte with one of the encryption bytes. The user will have to know the encryption table contents in order to correctly decode the verification data. The encryption table itself cannot be read out. Reading the Signature bytes The signature bytes are read by the same procedure as a normal verification of locations 030h and 031h, except that P3.6 and P3.7 need to be pulled to a logic low. The values are: (030h) = 15h; indicates manufacturer (Philips) (031h) = 92h/97h/BBh/BDh; indicates P87C51X2/52X2/54X2/ 58X2. Program/Verify Algorithms Any algorithm in agreement with the conditions listed in Table 9, and which satisfies the timing specifications, is suitable. Security Bits With none of the security bits programmed the code in the program memory can be verified. If the encryption table is programmed, the code will be encrypted when verified. When only security bit 1 (see Table 10) is programmed, MOVC instructions executed from external program memory are disabled from fetching code bytes from the internal memory, EA is latched on Reset and all further programming of the EPROM is disabled. When security bits 1 and 2 are programmed, in addition to the above, verify mode is disabled. When all three security bits are programmed, all of the conditions above apply and all external program memory execution is disabled. Encryption Array 64 bytes of encryption array are initially unprogrammed (all 1s). ™Trademark phrase of Intel Corporation. |
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