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flash parallel programming, signature bytes, set-up modes – Rainbow Electronics T89C51RD2 User Manual

Page 64

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Rev. F - 15 February, 2001

64

T89C51RD2

Note: These functions can only be called by user’s code. The standard boot loader cannot decrease the security level.

8.9. FLASH Parallel Programming

8.9.1. Signature bytes

Four hardware read only registers have to be accessed with parallel static test modes (mode TMS) in order to
control the FLASH parallel programmimg:

Manufacturer code

Device ID # 1: Family code

Device ID # 2: Memories size and type

Device ID # 3: Name and revision

As these registers can only be accessed by hardware, they must be read by the parallel programmers and then
copied in the XAF in order to make their values accessible by software (ISP or API).

8.9.2. Set-up modes

In order to program and verify the FLASH or to read the signature bytes, the T89C51RD2 is placed in specific
set-up modes (See Figure 22).

Control and program signals must be held at the levels indicated in Table 37. and Table 38.(Please notice that
each mode is defined over the two tables