Freescale Semiconductor StarCore SC140 - Manual (Page 352)

A-38 SC140 DSP Core Reference Manual
ADR
ADR
Add and Round (DALU)
ADR
Description
Status and Conditions that Affect Instruction
Status and Conditions Changed by Instruction
Example
adr d3,d4
Operation Assembler Syntax
Rnd(Da + Dn)
→ Dn
ADR Da,Dn
ADR Da,Dn
Adds one source data register (Da) to another (Dn) and rounds the sum. The result is stored in the
destination data register (Dn). Rounding adjusts the LSB of the high part of the destination register
according to the value of the low part of the register and then zeros the low part. The boundary between the
high part and the low part changes with scaling. The two modes of the round function, Rnd(), are described
on page A-359.
Register Address Bit Name Description
SR[2] SM If set, selects 32-bit arithmetic saturation mode.
SR[3] RM Rounding mode
SR[5:4] S[1:0] The scaling mode bits determine which bits in the result are used in
the Ln bit calculation, and which bits are used in rounding.
Register Address Bit Name Description
EMR[2] DOVF Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Ln L If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
Register/Memory Address Before After
D3 $00 0034 A216
L4:D4 $0:$00 2000 0000 $0:$00 2035 0000
SR $00E0 0000
EMR $0000 0000