User guide

Arch Meter Corporation PS1000 Ver1.2
PS1000Rev. 1.2 May 2006
25/ 67
www.archmeter.com
7. MCU
The PS1000 has one high performance 8-bit 8051 MCU. This MCU has 64KB
program space and 16KB data space. It also has 256B internal data space. The PS1000
MCU is fully compatible with general purpose 8051 MCU. Except the stand MCU, the
PS1000 MCU still have some more special functional block for the performance and
I/O enhancement.
For the standard MCU parts, please reference the 8051 user’s manual. The
following description only focus on the different parts.
7.1 32-bit ALU
PS1000 MCU had built-in one 32-bit ALU. This ALU can perform the 32 bits
ADD, SUB, MUL, DIV, Shift and Rotate. It can make the 8051 more efficient for the 32
bits arithmetic operation. The ALU can control by the ALUOP SFR register. When the
ALU is not used, the operand A and B in the SFR can play as internal register. The
configuration of ALUOP is shown below
ALUOP(SFR 0x9B)
B7 B6 B5 B4 B3 B2 B1 B0
EN BUSY MODE CI OPCODE
EN: ALU operation control
1: ALU start operate
0: ALU Ready/operation
BUSY: ALU BUSY Flag
1: ALU Busy
0: ALU ready for next instruction
MODE: Operand A/B Mode control
0: A/B maps to ALU output C/D output when the SFR read
1: A/B does not map to ALU C/D output, it plays as register
CI: Carry input