Signal processing device and method for supplying a signal processing result to a plurality of registers
A signal processing device and method of supplying a signal processing result to a plurality of registers arranged in different register files. A plurality of different register files are selected based on a corresponding indication in said instruction word and the register address is supplied to said selected register files. Result values can be broadcasted to multiple registers in a single processor cycle while a copy operation between different register files is eliminated. Broadcasting is thus implemented via overlapping register address spaces, since physical registers having the same logical register address are provided in different register files.
1. A signal processing device comprising a plurality of functional units (UC 1 –UCn) for processing digital data based on an instruction word,
a plurality of register files (RF 1 –RFn) for storing results obtained from said functional units, wherein said functional units are arranged to write a result to a predetermined register of said register files by using a register address (RRI) derived from said instruction word, and
register allocation means (RA) for selecting at least two of said register files (RF 1 –RFn) and for supplying said register address to said selected register files, based on a corresponding indication in said instruction word, wherein said indication providing information for selecting which of said at least two register files.
2. The device according to claim 1 , wherein said functional units (UC 1 –UCn) are arranged to supply said corresponding indication to said register allocation means (RA).
3. The device according to claim 1 , wherein said signal processing device is a programmable VLIW processor, and said register files are partitioned register files (RF 1 –RFn), wherein a data stationary instruction encoding is used.
4. The device according to claim 1 , wherein said corresponding indication is an information stating that said result is to be written to said register address of said selected register files.
5. The device according to claim 1 , wherein said corresponding indication is a result index (RI) which refers to a multicast or broadcast register in said selected register files.
6. The device according to claim 1 , wherein said register allocation means comprises demultiplexing means (DM 1 –DM 3 ) for demultiplexing said result and said register address (RRI) to said selected register files in response to said corresponding indication.
7. The device according to claim 1 , wherein said functional units are functional unit clusters (UC 1 –UCn).
8. A method of supplying a signal processing result to a plurality of registers arranged in different register files (RA 1 –RAn) of a signal processing device, said method comprising the steps of:
a) determining a register address (RRI) based on an instruction word,
b) supplying said register address to said plurality of register files, and,
c) selecting at least two of said plurality of register files based on a corresponding indication in said instruction word, wherein said indication providing information for selecting which of said at least two register files, and supplying said register address to said selected register files.
9. The method according to claim 8 , wherein said corresponding indication is an information stating that said result is to be written to said register address of said selected register files.
10. The method according to claim 8 , wherein said corresponding indication is a result index (RI) which refers to a multicast or broadcast register in said selected register files.