ace1202 Fairchild Semiconductor, ace1202 Datasheet - Page 12

• Manufacturer Part Number: ace1202
• Description: Arithmetic Controller Engine Acex ?for Low Power Applications
• Manufacturer: Fairchild Semiconductor

ACE1202 Product Family Rev. B.1
The ACEx microcontroller core is specifically designed for low
cost applications involving bit manipulation, shifting and block
encryption.It is based on a modified Harvard architecture meaning
peripheral, I/O, and RAM locations are addressed separately from
instruction data.
The core differs from the traditional Harvard architecture by
aligning the data and instruction memory sequentially. This allows
the X-pointer (12-bits) to point to any memory location in either
A
X
PC
SP
SR
11
10
R
7
0
0
G
3
Z
C
H
N
0
0
0
0
8-bit accumulator register
12-bit X pointer register
11-bit program counter
4-bit stack pointer
8-bit status register
NEGATIVE flag
HALF CARRY flag (from bit 3)
CARRY flag (from MSB)
ZERO flag
GLOBAL Interrupt Mask
READY flag (from EEPROM)
segment of the memory map. This modification improves the
overall code efficiency of the ACEx microcontroller and takes
advantage of the flexibility found on Von Neumann style ma-
chines.
The ACEx microcontroller has five general-purpose registers.
These registers are the Accumulator (A), X-Pointer (X), Program
Counter (PC), Stack Pointer (SP), and Status Register (SR). The
X, SP, and SR registers are all memory-mapped.
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