Semiconductor device chip selection
A method for accessing a plurality of DRAM devices each having a plurality of banks, the plurality of DRAM devices being interconnected to receive common address and command signals. The method includes receiving a first chip selection address and a first bank address with an active command to activate a first bank in a first DRAM device of the plurality of DRAM devices. A first bank active flag is set, corresponding to the first bank address, in the first DRAM device of the plurality of DRAM devices. A second bank address with a column command is received. A second bank is accessed in a second DRAM device of the plurality of DRAM devices having a set bank active flag corresponding to the second bank address.
1. A controller for a stacked dynamic random access memory (DRAM) device, the stacked DRAM device having a plurality of DRAM chips;
wherein the controller is configured to provide bank selection information to the stacked DRAM device by:
transmitting an external command to the stacked DRAM device, the external command including a row address strobe signal, a column address strobe signal, a write enable signal, and a chip select signal; and
transmitting an external address to the stacked DRAM device, the external address including a plurality of chip selection address bits, a plurality of row or column address bits, and a plurality of bank selection address bits;
wherein the bank selection information:
indicates that a bank identified by the plurality of bank selection address bits is to be activated in a selected DRAM chip identified by the plurality of chip selection address bits; and
causes the selected DRAM chip to store an indication of the bank selection information in a register in response to the indication being received concurrently with activation information corresponding to the bank selection information.
2. The controller of claim 1 , wherein the plurality of chip selection address bits and the plurality of row or column address bits are configurable to different ones of the external address terminals.
3. The controller of claim 1 , wherein the plurality of chip selection address bits comprises three chip selection address bits.
4. The controller of claim 3 , wherein the plurality of DRAM chips comprises eight DRAM chips.
5. The controller of claim 1 , wherein the external command is a read command and wherein the controller is further configured to receive read data from the bank indicated by the bank selection information.
6. The controller of claim 1 , wherein the external command is a write command and wherein the controller is further configured to transmit write data to the bank indicated by the bank selection information.
7. A system comprising:
a stacked DRAM device; and
a controller;
wherein the controller is configured to provide bank selection information to the stacked DRAM device by:
transmitting an external command to the stacked DRAM device, the external command including a row address strobe signal, a column address strobe signal, a write enable signal, and a chip select signal;
transmitting an external address to the stacked DRAM device, the external address including a plurality of chip selection address bits, a plurality of row or column address bits, and a plurality of bank selection address bits; and
causing a DRAM chip identified by the plurality of chip selection address bits to:
store an indication of the bank selection information in a register in response to the indication being received concurrently with activation information corresponding to the bank selection information; and
activate a bank identified by the plurality of bank selection address bits.
8. The system of claim 7 , wherein the plurality of chip selection address bits and the plurality of row or column address bits are configurable to different ones of the external address terminals.
9. The system of claim 7 , wherein the plurality of chip selection address bits comprises three chip selection address bits.
10. The system of claim 7 , wherein the plurality of DRAM chips comprises eight DRAM chips.
11. The system of claim 7 , wherein the external command is a read command and wherein the controller is further configured to receive read data from the bank indicated by the bank selection information.
12. The system of claim 7 , wherein the external command is a write command and wherein the controller is further configured to transmit write data to the bank indicated by the bank selection information.