Method of scheduling requests to banks in a flash controller

A method of scheduling a distribution of commands to a first and a second memory bank, the method comprising:

• making a first selection, by a hardware logic block, of a first command to send to a first NAND bank over a channel,
• transmitting the first command to the first NAND bank over the channel;
• estimating, by the hardware logic block, a time remaining in execution of the first command from a plurality of direct hardware inputs;
• making a second selection, by the hardware logic block, of a second command to send to a second NAND bank over the channel, based on the estimated time remaining of the first command;
• and
• transmitting the second command to the second NAND bank over the channel.

A method of determining a bank scheduling order for a NAND device having a plurality of banks with a shared channel, the method comprising:

• setting an input register to a first priority rule;
• setting an operation request to determine a first status of (1) the plurality of banks and (2) a plurality of command queues;
• determining whether the first priority rule and the operation request is sufficient to select a bank to receive a command;
• in response to determining that a bank can be selected to receive the command according to the first priority rule and the operation request,
• checking an operation status for the bank scheduled to receive the command, and
• transmitting the command to the bank when the operation status is not busy;
• in response to determining that a bank cannot be selected to receive the command according to the first priority rule and operation request,
• setting the input register to a second priority rule, and
• setting an operation request to determine a second status of (1) the plurality of banks and (2) the plurality of command queues,
• determining that the second priority rule and operation request is sufficient to select a bank to receive a second command, and
• transmitting the second command to the selected bank.