Maxim Integrated MAX31782 - Manual (Page 27)

MaximIntegrated 3-9
MAX31782 User’s Guide
Revision 0; 8/11
3.1.10AccumulatornRegister(A[n],9h[nh])
Initialization: This register is cleared to 0000h on all forms of reset .
Access: Unrestricted direct read/write access .
3.1.11PrefixRegister(PFX[n],Bh[n])
Initialization: This register is cleared to 0000h on all forms of reset .
Access: Unrestricted direct read/write access .
3.1.12InstructionPointerRegister(IP,Ch[0h])
Initialization: This register is cleared to 8000h on all forms of reset .
Access: Unrestricted direct read/write access .
BIT FUNCTION
A[n] .[15:0]
This register acts as the accumulator for all ALU arithmetic and logical operations when selected by the
accumulator pointer (AP) . It can also be used as a general-purpose working register .
BIT FUNCTION
PFX[n] .[15:0]
The Prefix register provides a means of supplying an additional 8 bits of high-order data for use by the
succeeding instruction as well as providing additional indexing capabilities . This register only holds any
data written to it for one execution cycle, after which it reverts to 0000h . Although this is a 16-bit register,
only the lower 8 bits are actually used for prefixing purposes by the next instruction . Writing to or reading
from any index in the prefix module selects the same 16-bit register . However, when the PFX register is
written, the index n used for the PFX[n] write also determines the high-order bits for the register source
and destination specified in the following instruction .
WRITE TO
SOURCE, DESTINATION INDEX SELECTION
SOURCE REGISTER RANGE DESTINATION REGISTER RANGE
PFX[0] 0h to Fh 0h to 7h
PFX[1] 10h to 1Fh 0h to 7h
PFX[2] 0h to Fh 8h to Fh
PFX[3] 10h to 1Fh 8h to Fh
PFX[4] 0h to Fh 10h to 17h
PFX[5] 10h to 1Fh 10h to 17h
PFX[6] 0h to Fh 18h to 1Fh
PFX[7] 10h to 1Fh 18h to 1Fh
The index selection reverts to 0 (default mode allowing selection of registers 0h to 7h for destinations)
after one cycle in the same manner as the contents of the PFX register .
BIT FUNCTION
IP .[15:0]
This register contains the address of the next instruction to be executed and is automatically incremented
by 1 after each program fetch . Writing an address value to this register caused program flow to jump to
that address . Reading from this register does not affect program flow .