Abstract: A memory management unit suitable fo use in a digital signal processor having internal and eternal memories is described. The unit is especially designed to facilitate numeric algorithms such as fast fourier transforms, auto-correlation and digital filtering by relieving the programmer from the need to monitor memory accesses. Automatic post-updating of memory addresses is provided after indirect memory references. Also, memory boundary-checking is performed according to a user-specified modulus value, and a memory reference is automatically adjusted to fall within the user-specified address range. A dual-access register file stores initial memory addresses and their associated modulus values and in a dual-bus embodiment a pair of address generation units provides post-updates of the addresses stored in the register files.

Abstract: A memory management unit suitable for use in a digital signal processor has internal and eternal memories is described. The unit is especially designed to facilitate numeric algorithms such as fast fourier transforms, auto-correlation and digital filtering by relieving the programmer from the need to moniter memory accesses. Automatic post-updating of memory addresses is provided after indirect memory references. Also, memory boundary-checking is performed according to a user-specified modulus value, and a memory reference is automatically adjusted to fall within the user-specified address range. A dual-access register file stores initial memory addresses and their associated modulus values and in a dual-bus embodiment a pair of address generation units provides post-updates of the addresses stored in the register files.

Abstract: A storage device capable of being configured either as a single-access memory or as two separate memories is described. The storage device is especially suited for use in a digital signal processor performing numeric algorithms such as fast fourier transforms, autocorrelation and digital filtering because certain of such algorithms require fast dual access to two correlated, but separate, parameters while other such algorithms require fast single access to identical parameters. The storage device is shown in an exemplary embodiment empolying a multiplexer to affect writing of data from either of two data busses to one of the memories. In a second embodiment the write port of the memory is connected to one bus and the read port is connected to both busses. In this embodiment a dual-port address register file and a pair of address generation units provide indirect addressing capability for the storage device. Method of operating separate memories in a single-access or a dual-access mode is also described.