Abstract: A phase training update circuit operates to perform a phase training update on individual bit lanes. The phase training update circuit adjusts a bit lane transmit phase offset forward a designated number of phase steps, transmits a training pattern, and determines a first number of errors in the transmission. It also adjusts the bit lane transmit phase offset backward the designated number of phase steps, transmits the training pattern, and determines a second number of errors in the transmission. Responsive to a difference between the first number of errors and the second number of errors, the phase training update circuits adjusts a center phase position for the bit lane transmit phase offset of the selected bit lane.

Abstract: A phase training update circuit operates during a self-refresh cycle of a memory to perform a phase training update on individual bit lanes. The phase training update circuit adjusts a bit lane transmit phase offset forward a designated number of phase steps, transmits a training pattern, and determines a first number of errors in the transmission. It also adjusts the bit lane transmit phase offset backward the designated number of phase steps, transmits the training pattern, and determines a second number of errors in the transmission. Responsive to a difference between the first number of errors and the second number of errors, the phase training update circuits adjusts a center phase position for the bit lane transmit phase offset of the selected bit lane.

Abstract: A phase training update circuit operates during a self-refresh cycle of a memory to perform a phase training update on individual bit lanes. The phase training update circuit adjusts a bit lane transmit phase offset forward a designated number of phase steps, transmits a training pattern, and determines a first number of errors in the transmission. It also adjusts the bit lane transmit phase offset backward the designated number of phase steps, transmits the training pattern, and determines a second number of errors in the transmission. Responsive to a difference between the first number of errors and the second number of errors, the phase training update circuits adjusts a center phase position for the bit lane transmit phase offset of the selected bit lane.

Abstract: In one form, a memory controller includes a command queue, an arbiter, and a replay queue. The command queue receives and stores memory access requests. The arbiter is coupled to the command queue for providing a sequence of memory commands to a memory channel. The replay queue stores the sequence of memory commands to the memory channel, and continues to store memory access commands that have not yet received responses from the memory channel. When a response indicates a completion of a corresponding memory command without any error, the replay queue removes the corresponding memory command without taking further action. When a response indicates a completion of the corresponding memory command with an error, the replay queue replays at least the corresponding memory command. In another form, a data processing system includes the memory controller, a memory accessing agent, and a memory system to which the memory controller is coupled.

Abstract: A data processing system includes a memory channel and a data processor coupled to the memory channel. The data processor includes a memory controller coupled to the memory channel and is adapted to access at least one rank of double data rate memory. The memory controller includes a command queue for storing received memory access requests, and an arbiter for picking memory access requests from the command queue, and then providing the memory access requests to the memory channel. The memory access requests are selected based on predetermined criteria, and in response to a mode register access request to quiesce pending operations. Additionally, the memory controller includes a mode register access controller that in response to the mode register access request, generates at least one corresponding mode register set command to a memory bus. The memory controller then relinquishes control of the memory bus to the arbiter thereafter.

Abstract: A data processing system includes a memory channel and a data processor coupled to the memory channel. The data processor includes a memory controller coupled to the memory channel and is adapted to access at least one rank of double data rate memory. The memory controller includes a command queue for storing received memory access requests, and an arbiter for picking memory access requests from the command queue, and then providing the memory access requests to the memory channel. The memory access requests are selected based on predetermined criteria, and in response to a mode register access request to quiesce pending operations. Additionally, the memory controller includes a mode register access controller that in response to the mode register access request, generates at least one corresponding mode register set command to a memory bus. The memory controller then relinquishes control of the memory bus to the arbiter thereafter.

Abstract: In one form, a memory controller includes a command queue, an arbiter, and a replay queue. The command queue receives and stores memory access requests. The arbiter is coupled to the command queue for providing a sequence of memory commands to a memory channel. The replay queue stores the sequence of memory commands to the memory channel, and continues to store memory access commands that have not yet received responses from the memory channel. When a response indicates a completion of a corresponding memory command without any error, the replay queue removes the corresponding memory command without taking further action. When a response indicates a completion of the corresponding memory command with an error, the replay queue replays at least the corresponding memory command. In another form, a data processing system includes the memory controller, a memory accessing agent, and a memory system to which the memory controller is coupled.