8XC196L
X

SUPPLEMENT

3-2
3.2 REGISTER FILEFigure 3-1 compares the register file addresses of the 8XC196Lx and 8XC196Kx. The registerfile in Figure 3-1 is divided into an upper register file and a lower register file. Th e upper registerfile consists of general-purpose register RAM. The lower register file contains general-purposeregister RAM along with the stack pointer (SP) and the CPU special-function registers (SFRs). Table 3-2 lists the register file memory addresses. The RALU accesses the lower register file di-rectly, without the use of the memory controller. It also accesses a windowed location directly(see “Windowing” on page 3-6). The upper register file and the peripheral SFRs can be win-dowed. Registers in the lower register file and registers being windowed can be accessed withregister-direct addressing.

NOTE

The register file must not contain code. An attempt to execute an instruction from a location in the register file causes the memory controller to fetch the instruction from external memo ry.
1BFF
0500 1BFF
0500 1BFF
0600 1BFF
0600 1BFF
0600
External device (memory
or I/O) connected to
address/data bus
Indirect or
indexed
04FF
0400 04FF
0400 ——
05FF
0400 05FF
0400 Internal code or data RAM Indirect or
indexed
03FF
0200 05FF
0180 ———
External device (memory
or I/O) connected to
address/data bus
Indirect or
indexed
03FF
0100 01FF
0100 017F
0100 02FF
0100 03FF
0100 03FF
0100
Upper register file
(general-purpose register
RAM)
Indirect,
indexed, or
windowed
direct
00FF
0000 00FF
0000 00FF
0000 00FF
0000 00FF
0000 00FF
0000
Lower register file
(register RAM, stack
pointer, and CPU SFRs)
Direct,
indirect, or
indexed

Table 3-1. Address Map (Continued)

Device and Hex Address Range
Description Addressing
Modes
CA
JR, KR
LD
LA, LB
JT, KT
JV
NOTES:
1. After a reset, the device fetches its first instruction from 2080H.
2. The content or function of these locations may change in future device revisions, in which case
a program that relies on a location in this range might not function properly.