User guide

DS4830A User’s Guide
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3.21 – General Register Byte-Swapped (GRS, 0Eh[08h])
Initialization: This register is cleared to 0000h on all forms of reset
Access: Unrestricted read-only access.
BIT
DESCRIPTION
15:0
This register is intended primarily for supporting byte operations on 16-bit data. This 16-bit read
only register returns the byte-swapped value for the data contained in the GR register.
3.22 – General Register High Byte (GRH, 0Eh[09h])
Initialization: This register is cleared to 00h on all forms of reset.
Access: Unrestricted direct read/write access.
BIT
DESCRIPTION
7:0
This register reflects the high byte of the GR register and is intended primarily for supporting byte
operations on 16-bit data. Any data written to the GRH register will also be stored in the high byte
of the GR register.
3.23 – General Register Sign Extended Low Byte (GRXL, 0Eh[0Ah])
Initialization: This register is cleared to 0000h on all forms of reset.
Access: Unrestricted direct read-only access.
BIT
DESCRIPTION
15:0
This register provides the sign extended low byte of GR as a 16-bit source.
3.24 – Frame Pointer Register (FP, 0Eh[0Bh])
Initialization: This register is cleared to 0000h on all forms of reset.
Access: Unrestricted direct read-only access.
BIT
DESCRIPTION
15:0
This register provides the current value of the frame pointer (BP[Offs]).
3.25 – Data Pointer 0 Register (DP[0], 0Fh[03h])
Initialization: This register is cleared to 0000h on all forms of reset.
Access: Unrestricted direct read/write access.
BIT
DESCRIPTION
15:0
This register is used as a pointer to access data memory. DP[0] can be automatically incremented
or decremented following each read operation or can be automatically incremented or
decremented before each write operation.
3.26 – Data Pointer 1 Register (DP[1], 0Fh[07h])
Initialization: This register is cleared to 0000h on all forms of reset.
Access: Unrestricted direct read/write access.
BIT
DESCRIPTION
15:0
This register is used as a pointer to access data memory. DP[1] can be automatically incremented
or decremented following each read operation or can be automatically incremented or
decremented before each write operation.