Memory Organization - Philips P89LPC938 User Manual

Philips Semiconductors

1.4 Memory organization

FF00h
IAP entry-
FFEFh points
ISP CODE
1FFFh
(512B)*
1E00h
SECTOR 7
1C00h
1BFFh
SECTOR 6
1800h
17FFh
SECTOR 5
1400h
13FFh
SECTOR 4
1000h
0FFFh
SECTOR 3
0C00h
0BFFh
SECTOR 2
0800h
07FFh
SECTOR 1
0400h
03FFh
SECTOR 0
0000h
Fig 5. P89LPC938 memory map.
The various P89LPC938 memory spaces are as follows:
DATA — 128 bytes of internal data memory space (00h:7Fh) accessed via direct or
indirect addressing, using instruction other than MOVX and MOVC. All or part of the Stack
may be in this area.
IDATA — Indirect Data. 256 bytes of internal data memory space (00h:FFh) accessed via
indirect addressing using instructions other than MOVX and MOVC. All or part of the
Stack may be in this area. This area includes the DATA area and the 128 bytes
immediately above it.
SFR — Special Function Registers. Selected CPU registers and peripheral control and
status registers, accessible only via direct addressing.
CODE — 64 kB of Code memory space, accessed as part of program execution and via
the MOVC instruction. The P89LPC938 has 8 kB of on-chip Code memory.
Table 4:
Type
DATA
IDATA
User manual
Read-protected
IAP calls only
FFEFh
IDATA routines
entry points for:
FF1Fh
entry
-51 ASM. code
points
-C code
FF00h
1FFFh
ISP serial loader
entry points for:
-UART (auto-baud)
-I2C, SPI, etc.*
1E00h
Flexible choices:
-as supplied (UART)
-Philips libraries*
-user-defined
Data RAM arrangement
Data RAM
Directly and indirectly addressable memory
Indirectly addressable memory
Rev. 03 — 7 June 2005
IDATA (incl. DATA)
SPECIAL FUNCTION
REGISTERS
(DIRECTLY ADDRESSABLE)
DATA
DIRECT AND INDIR. ADDR.)
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
UM10119
P89LPC938 User manual
128 BYTES ON-CHIP
DATA MEMORY (STACK
AND INDIR. ADDR.)
128 BYTES ON-CHIP
DATA MEMORY (STACK,
4 REG. BANKS R[7:0]
data memory
(DATA, IDATA)
002aaa948
Size (bytes)
128
256
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