Memory command that specifies one of multiple possible write data values where the write data is not transported over a memory data bus
An apparatus is described. The apparatus includes a memory controller having an interface to communicate with a memory. The memory controller comprising logic circuitry to specify one of multiple possible write values to the memory during a write operation with multiple bits of a command that is sent on a command address bus that emanates from the interface. The memory to write any one of the possible write values into its storage cells while the memory interface is in a power saving state wherein the specified one write value is not articulated by the memory controller on a data bus of the interface as part of the write operation.
1. An apparatus, comprising:
a memory controller having an interface to communicate with a memory, the memory controller comprising logic circuitry to specify one of multiple possible write values to the memory during a write operation with multiple bits of a command that is sent on a command address bus that emanates from the interface, the memory to write any one of the possible write values into its storage cells while the interface is in a power saving state,
wherein the specified one write value is not articulated by the memory controller on a data bus of the interface as part of the write operation.
2. The apparatus of claim 1 , wherein the command is not a WRITE command.
3. The apparatus of claim 2 , wherein the command is a command/address bus (CAS) command and the interface is compatible with a Joint Electron Device Engineering Council (JEDEC) promulgated industry standard.
4. The apparatus of claim 3 , wherein the JEDEC promulgated standard is a low power dual data rate 5 (LPDDR5) standard.
5. The apparatus of claim 1 , wherein the power saving state comprises:
not sending write data over the interface;
not sending write strobes over the interface; and
inactivated memory side on-die termination circuitry.
6. The apparatus of claim 1 , wherein the memory comprises look-up table circuitry having entries, the one write value provided by a particular one of the entries identified by the multiple bits.
7. The apparatus of claim 1 , wherein the specified one write value is communicated in a second command that precedes a WRITE command in a normal write sequence, and wherein the specified one write value are all 1s.
8. The apparatus of claim 7 , wherein the specified write value is communicated with less bits than a size of a data word to be written, and wherein the memory includes hardwired circuitry to create the specified one write value.
9. The apparatus of claim 7 , wherein the specified one write value is embedded in the second command.
10. A computing system, comprising:
a network interface;
a plurality of processing cores;
a memory;
a memory controller having an interface to communicate with the memory, the memory controller comprising logic circuitry to specify one of multiple possible write values to the memory during a write operation with multiple bits of a command that is sent on a command address bus that emanates from the interface, the memory to write any one of the possible write values into its storage cells while the interface is in a power saving state,
wherein the specified one write value is not articulated by the memory controller on a data bus of the interface as part of the write operation.
11. The computing system of claim 10 , wherein the command is not a WRITE command.
12. The apparatus of claim 11 , wherein the command is a command/address bus (CAS) command, wherein the interface is compatible with a Joint Electron Device Engineering Council (JEDEC) promulgated industry standard, and wherein the JEDEC promulgated standard is low power dual data rate 5 (LPDDR5) standard.
13. The computing system of claim 10 wherein the multiple possible write values comprise:
all 1s; and
all 0 s.
14. The computing system of claim 10 , wherein the memory comprises look-up table circuitry having entries, the one write value provided by a particular one of the entries identified by the multiple bits.
15. The computing system of claim 14 , wherein the specified write value is communicated with less bits than a size of a data word to be written, and wherein the memory includes hardwired circuitry to create the specified one write value, and wherein the specified one write value are all 1s.
16. The computing system of claim 10 , wherein the specified value is embedded in the command.
17. A memory, comprising:
storage cells;
an interface to communicate with a memory controller; and
logic circuitry to comprehend one write value of multiple possible write values to be written to the storage cells during a write operation with multiple bits of a command that is sent on a command address bus that flows into the interface, the logic circuitry to write any one of the multiple possible write values into the storage cells while the interface is in a power saving state,
wherein the one write value is not articulated by the memory controller on a data bus of the interface as part of the write operation.
18. The memory of claim 17 , wherein the command precedes a WRITE command in a normal write sequence.
19. The memory of claim 17 , wherein the one write value is communicated with less bits than a size of a data word to be written and the memory further includes hardwired circuitry to create the one write value.
20. The memory of claim 17 , wherein the memory further comprises a look-up table circuitry having entries, the one write value provided by a particular one of the entries identified by the multiple bits.