Intel 8XC196NT, 87C196CB Selecting Bank 0 FF2000-FF7FFFH, Selecting Bank 1 FF8000-FFFFFFH

Models: 8XC196NT 87C196CB

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Serial Port Programming Mode

87C196CB SUPPLEMENT

Table 10-4. Serial Port Programming Mode Memory Map

Description

 

Address Range

 

 

Normal Operation

Serial Port Programming Mode

 

 

 

 

Internal OTPROM

FF2000–FF7FFFH

A000–FFFFH (bank 0; 1FF9H = 00H)

FF8000–FFFFFFH

8000–FFFFH (bank 1; 1FF9H = 80H)

 

 

 

 

External memory

4000–7FFFH

 

 

 

Do not address

2400–3FFFH

 

 

 

Test ROM and RISM

2000–23FFH

 

 

 

The lower 24 Kbytes of OTPROM (FF2000–FF7FFFH) are remapped to A000–FFFFH, and the upper 32 Kbytes (FF8000–FFFFFFH) are mapped to 8000–FFFFH. A bank switching mecha- nism differentiates between the two address ranges. The most-significant bit of an otherwise re- served byte register (location 1FF9H) selects the bank. Bank 0 is the lower 24 Kbytes, and bank 1 is the upper 32 Kbytes. To program the lower 24 Kbytes, you must write 00H to location 1FF9H. To program the upper 32 Kbytes, you must write 80H to location 1FF9H. (See page 10-4 for the required command sequences.)

WARNING

Writing any value other than 00H or 80H to location 1FF9H will cause the microcontroller to enter an unsupported test mode.

10.4.1 Selecting Bank 0 (FF2000–FF7FFFH)

Send the following RISM command sequence to select bank 0.

Code Description

1F DATA. High byte of address to DATA register.

F9 DATA. Low byte of address to DATA register.

0A DATA_TO_ADDR. Move address from DATA register to ADDR register.

00SET_DLE_FLAG. The next data byte is <1FH.

00DATA. Data to clear the most-significant bit.

07WRITE_BYTE. Move data from the DATA register to memory location 1FF9H.

10.4.2 Selecting Bank 1 (FF8000–FFFFFFH)

Send the following RISM command sequence to select bank 1.

Code Description

1F DATA. High byte of address to DATA register.

F9 DATA. Low byte of address to DATA register.

0A DATA_TO_ADDR. Move address from DATA register to ADDR register.

80 DATA. Data to set the most-significant bit.

07 WRITE_BYTE. Move data from the DATA register to memory location 1FF9H.

10-4

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Intel 8XC196NT, 87C196CB Selecting Bank 0 FF2000-FF7FFFH, Selecting Bank 1 FF8000-FFFFFFH, Serial Port Programming Mode