ATA6020N ATMEL Corporation, ATA6020N Datasheet - Page 4

• Manufacturer Part Number: ATA6020N
• Description: Low-current Microcontroller For Watchdog Function
• Manufacturer: ATMEL Corporation

4.1
4.1.1
4
Components of MARC4 Core
ATA6020N
ROM
The core contains ROM, RAM, ALU, a program counter, RAM address registers, an instruction
decoder and interrupt controller. The following sections describe each functional block in more
detail:
The program memory (ROM) is mask programmed with the customer application program dur-
ing the fabrication of the microcontroller. The ROM is addressed by a 12-bit wide program
counter, thus predefining a maximum program bank size of 2 Kbytes. An additional 1-Kbyte of
ROM exists, which is reserved for quality control self-test software The lowest user ROM
address segment is taken up by a 512-byte Zero page which contains predefined start
addresses for interrupt service routines and special subroutines accessible with single byte
instructions (SCALL).
The corresponding memory map is shown in
held in ROM and are accessed via the MARC4's built-in TABLE instruction.
Figure 4-2.
1FFh
000h
7FFh
ROM Map of ATA6020N
Zero page
(2 K x 8 bit)
ROM
Figure
4-2. Look-up tables of constants can also be
1F8h
1E8h
1E0h
020 h
018h
010h
000 h
1F0h
008h
Z er o
page
1E0h
1C 0h
180h
140h
100h
0C 0h
080h
040h
008h
000h
I N T 6
I N T 3
I N T 7
I N T 5
I N T 4
I N T 2
I N T 1
I N T 0
$R E SE T
$A U T O SL E E P
4708D–4BMCU–09/05