Method of performing access to a single-port memory device, memory access device, integrated circuit device and method of use of an integrated circuit device
View Patent ↗An arbiter 15 for accessing a single-port RAM 13 without the need to use a hand-shaking protocol is proposed. This allows simultaneous read and write accesses to a single-port RAM 13 . All write accesses are delayed so that the arbiter 15 can detect if there is a simultaneous read access. If there is a read access, the read access is delayed until the write access is completed.
1. Method of performing access to a single-port memory device, the method comprising the steps of:
providing a memory access device to control the access,
processing a first access-signal (WEN) of high priority at a first clock rate,
processing a second access-signal (REBL) of low priority at a second clock rate,
wherein the first clock rate exceeds the second clock rate,
providing direct access to the memory device for the first access-signal (WEN) of high priority, and
properly delaying the first access-signal (WEN) of high priority to generate an access-timing according to the demands of the memory device.
2. Method according to claim 1 , characterized in that access to the memory device for the second access-signal (REBL) of low priority is generally provided, except in the case that an access of a first access-signal (WEN) of high priority is in preparation and/or in process, to guarantee direct access to the memory device for the first access-signal (WEN) of high priority.
3. Method according to claim 1 , characterized in that in the case that access to the memory device is not provided for the second access-signal (REBL) of low priority, the second access-signal (REBL) is backed up.
4. Method according to one of claim 1 , characterized in that in the case that access to the memory device is not provided for the second access-signal (REBL) of low priority, direct access to the memory device is made by the first access-signal (WEN) of high priority and/or after completion of an access to the memory device by the first access-signal (WEN) of high priority access is made by the second access-signal of low priority.
5. Method according to claim 4 , characterized in that the completion of the access made by the first access-signal (WEN) of high priority is used to introduce the access of the second access-signal (REBL) of low priority.
6. Method according to one of claim 1 , characterized in that the proper delay of the first access-signal (WEN) of high priority is available from a number of delay periods (t 0 , t 1 , t 2 , t 3 ) offered for choice to generate an access-timing according to the demands of the memory device.
7. Method according to one of claim 1 , characterized in that a time gap in between two subsequent accesses of first access-signals (WEN) of high priority is sufficiently wide to complete an access of a second access-signal of low priority (REBL) therein.
8. Method according to one of claim 1 , characterized in that the first access-signal (WEN) of high priority is a write-signal (WEN), in particular a write-enable signal (WEN) and/or the second access-signal (REBL) of low priority is a read-signal (REBL), in particular a read-enable signal (REBL).
9. Method according to one of the claim 1 , characterized in that the first clock rate is an external clock rate of the memory access device and/or the second clock rate is an internal clock rate (RAM-CLK) of the memory access device.
10. Memory access device for performing controlled access to a single-port memory device, comprising:
a first path for processing a first access-signal (WEN) of high priority at a first clock rate,
a second path for processing a second access-signal (REBL) of low priority at a second clock rate, wherein the first clock rate exceeds the second clock rate,
a control-assembly for providing direct access to the memory device for the first access-signal (WEN) of high priority,
a delay-assembly for properly delaying (t 0 , t 1 , t 2 , t 3 ) the first access-signal (WEN) of high priority adapted to generate an access-timing according to the demands of the memory device.
11. Memory access device according to claim 10 , characterized in that the first and/or second path comprises a number of control elements, in particular a logic gate and/or a flip-flop, functionally connected with each other and an input-interface and an output-interface.
12. Memory access device according to claim 10 , characterized in that at least the second path comprises a storage element to perform a back-up function.
13. Memory access device according to one of the claim 10 , characterized in that the control-assembly comprises at least one input-interface delay-assembly-signal and/or access-addresses and an output-interfaces to transmit an address-signal and/or a RAM-select signal.
14. Memory access device according to one of claim 10 , characterized in that the delay-assembly comprises a number of resistance-capacitor elements and/or buffer elements, in particular a chain thereof.
15. Memory access device according to one of claim 10 , characterized by a single external clock-rate input.
16. Integrated circuit device comprising:
a single-port memory device,
a means for supplying a first clock rate,
a single external-clock-rate input for supplying a second clock rate, and
a memory access device of one of the claims 10 for accessing the single-port memory device.
17. Integrated circuit device according to claim 16 , wherein the means for supplying a first clock rate comprises an internal timing controller.
18. Integrated circuit device according to claim 16 , characterized by comprising a number of single-port memory devices, each one of the number of single-port memory devices being addressable separately and/or a number of memory access devices each one of the number of single-port memory devices being related to one of the number of memory access devices, wherein in particular the number of memory access devices are identical to each other.
19. Method of use of an integrated circuit device, in particular of an integrated circuit device as claimed in claim 16 , as an application specific integrated circuit device, in particular for accessing a display device, in particular for use with regard to a display driver.