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3-1
CHAPTER 3
MEMORY PARTITIONS
This chapter describes the differences in the address space of the 87C196CB from that of the
8XC196NT. The 87C196CB has 56 Kbytes of one-time-programmable read-only memory (OT-
PROM), while the 8XC196NT is available with 32 Kbytes. The 87C196CB also has an additional
512 bytes of register RAM.
The 87C196CB is available in either an 84-pin or a 100-pin package. The 84-pin 87C196CB, like
the 8XC196NT, has up to 20 external address lines, enabling access to 1 Mbyte of linear address
space. The 100-pin 87C196CB has four additional pins available for external address lines. With
all 24 external address lines connected (A23:16 and AD15:0), the 100-pin 87C196CB can access
16 Mbytes of linear address space.
3.1 MEMORY MAP, SPECIAL-FUNCTION REGISTERS, AND WINDOWING
Table 3-1 compares the register file addresses of the 8XC196NT and 87C196CB. Table 3-2 is a
memory map of the 87C196CB. Table 3-3 lists the 87C196CB’s peripheral SFRs (these are the
same as those of the 8XC196NT). Table 3-4 lists the CAN peripheral SFRs, which are unique to
the 87C196CB. Tables 3-5 through 3-9 provide the information necessary to window higher
memory into the lower register file for direct access.
.
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Table 3-1. Register File Memory Addresses
Device and Hex
Address Range
Description Addressing Modes
CB NT
1DFF
1C00
— Register RAM Indirect, indexed, or windowed direct
03FF
0100
03FF
0100
Upper register file (register RAM) Indirect, indexed, or windowed direct
00FF
001A
00FF
001A
Lower register file (register RAM) Direct, indirect, or indexed
0019
0018
0019
0018
Lower register file (stack pointer) Direct, indirect, or indexed
0017
0000
0017
0000
Lower register file (CPU SFRs) Direct, indirect, or indexed