w83l950d Winbond Electronics Corp America, w83l950d Datasheet - Page 22

• Manufacturer Part Number: w83l950d
• Description: Peripheral Personal Computer Keyboard Controller
• Manufacturer: Winbond Electronics Corp America

6.7
The Winbond Keyboard controller includes one 40K bytes of main MTP-ROM for application program
(APROM). This reality on-chip MTP-ROM begins at address 0000h and continuous through 0AFFFh.
After reset, the micro-controller executes the new application program in the main MTP-APROM. The
addressing of Program Memory can up to 64K bytes long.
6.8
The Winbond Keyboard controller has a 256 bytes on-chip scratch pad RAM which architecture is
almost same as industry standard microprocessor 8052. This RAM begins at address 00h to 0FFh, can
be used for temporary storage during program execution.
From 00h to 1Fh, is divided into 4 Banks, which is used to provide 4 Register-sets, each bank has
individual R0 to R7. Only one Register-set is accessible at a time, which decided by the bit 4,3 of PSW,
RS1, RS0.
From 20h to 2Fh, is either a general Byte-addressable memory area or a specific purpose
Bit-addressable memory area. No control bit needed here. If it is accessed by a Bit-addressable
instruction, the range of bit address is from 00h to 7Fh in linearly to any bit-operational instruction.
From 30h to 7Fh, is a general memory area, which can be accessed by direct or indirect addressing.
From 80h to 0FFh is a special memory area, which can be accessed by only indirect addressing. At the
same location which also addressed from 80h to FFh, there is a Special Function Registers (SFRs)
Area, can be accessed by only direct addressing. This difference is to provide two physical memory
entities coexisted at the same address without contention occurred.
Program Memory
Scratch Pad RAM
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Publication Release Date: June 23, 2003
W83L950D
Revision 1.0