High speed interface for daisy-chained devices

Abstract

A plurality of devices are operated by storing at a device a first ID number received at a first port of the device and a second ID number received at a second port of the device. The device receives a data command through at least one of the first and second ports. The data command has a command ID number. The device executes the data command when at least one of the command ID number is equal to the first ID number when the data command is received at the first port and the command ID number is equal to the second ID number when the data command is received at the second port.

What is claimed is: 
     
         1 . A method for performing a write command on one of a plurality of memory devices, comprising:
 storing at each memory device a first ID number associated with a first port of the memory device and a second ID number associated with a second port of the memory device;   receiving, by the one memory device, a write command through at least one of the first and second ports, the write command having a first command ID number and being accompanied by write data;   writing the write data to a memory array of the one memory device when the first command ID number is equal to the first ID number and the write command is received at the first port; and   writing the write data to the memory array of the one memory device when the first command ID number is equal to the second ID number and the write command is received at the second port.   
     
     
         2 . The method of  claim 1 , wherein:
 writing the write data to the memory array of the one memory device comprises:
 writing the write data to a buffer of the one memory device; and 
 writing the write data from the buffer to the memory array. 
   
     
     
         3 . The method of  claim 1 , wherein:
 the plurality of memory devices are serially connected.   
     
     
         4 . The method of  claim 3 , further comprising:
 transmitting the write command without execution from the memory device through the second port, when the write command is received at the first port and the command ID is not equal to the first ID number; and   transmitting the write command without execution from the memory device through the first port when the write command is received at the second port and the command ID is not equal to the second ID number.   
     
     
         5 . The method of  claim 4 , wherein:
 writing the write data to the memory array of the one memory device comprises:
 receiving a first portion of the write data at the first port of the memory device; 
 writing the first portion of the write data to a first portion of the memory array; 
 receiving a second portion of the write data at the second port of the memory device; and 
 writing the second portion of the write data to a second portion of the memory array. 
   
     
     
         6 . The method of  claim 1 , further comprising:
 receiving, by the one memory device, a read command through the other of the first and second ports, the read command having a second command ID number;   outputting read data from the first port of the one memory device when the second command ID number is equal to the first ID number and the read command is received at the first port; and   outputting the read data from the second port of the one memory device when the second command ID number is equal to the second ID number and the read command is received at the second port.   
     
     
         7 . The method of  claim 6 , wherein:
 outputting the read data comprises transferring the read data from a buffer of the one memory device.   
     
     
         8 . The method of  claim 7 , wherein:
 outputting the read data comprises transferring the read data from the memory array of the one memory device.   
     
     
         9 . The method of  claim 6 , wherein:
 outputting the read data comprises transferring the read data from the memory array of the one memory device.   
     
     
         10 . The method of  claim 8 , further comprising:
 when the first command ID number and the second command ID number both correspond to respective ones of the first and second ID numbers of the one memory device, writing the write data to the memory array and transferring the read data from the memory array concurrently.   
     
     
         11 . The method of  claim 9 , further comprising:
 when the first command ID number and the second command ID number both correspond to respective ones of the first and second ID numbers of the one memory device, writing the write data to the memory array and transferring the read data from the memory array concurrently.   
     
     
         12 . A method for performing a read command on one of a plurality of memory devices, comprising:
 storing at each memory device a first ID number received at a first port of the memory device and a second ID number associated with a second port of the memory device;   receiving, by the one memory device, a read command through at least one of the first and second ports, the read command having a command ID number;   outputting read data from the one memory device when the command ID number is equal to the first ID number and the read command is received at the first port; and   outputting the read data from the one memory device when the command ID number is equal to the second ID number and the read command is received at the second port.   
     
     
         13 . The method of  claim 12 , wherein:
 outputting the read data comprises:
 reading the read data from a buffer of the one memory device; and 
 outputting the read data from the one memory device. 
   
     
     
         14 . The method of  claim 13 , wherein:
 reading the read data from a buffer of the one memory device comprises:
 transferring the read data from the memory array to the buffer. 
   
     
     
         15 . The method of  claim 12 , wherein:
 the plurality of memory devices are serially connected.   
     
     
         16 . The method of  claim 15 , further comprising:
 transmitting the read command without execution from the memory device through the second port, when the read command is received at the first port and the command ID is not equal to the first ID number; and   transmitting the read command without execution from the memory device through the first port when the read command is received at the second port and the command ID is not equal to the second ID number.   
     
     
         17 . The method of  claim 16 , wherein:
 outputting the read data from the one memory device comprises:
 outputting a first portion of the read data from the one memory device through the first port; and 
 outputting a second portion of the read data from the one memory device through the second port. 
   
     
     
         18 . The method of  claim 17 , wherein:
 outputting the read data from the one memory device comprises:
 delaying one of the first portion and the second portion by a number of clock cycles equal to a difference between the first ID number and the second ID number. 
   
     
     
         19 . The method of  claim 12 , further comprising:
 receiving, by the one memory device, a write command through the other of the first and second ports, the write command having a second command ID number and being accompanied by write data;   writing the write data to a memory array of the one memory device when the second command ID number is equal to the first ID number and the write command is received at the first port; and   writing the write data to the memory array of the one memory device when the second command ID number is equal to the second ID number and the write command is received at the second port.   
     
     
         20 . The method of  claim 14 , further comprising:
 receiving, by the one memory device, a write command through the other of the first and second ports, the write command having a second command ID number and being accompanied by write data;   writing the write data to a memory array of the one memory device when the second command ID number is equal to the first ID number and the write command is received at the first port; and   writing the write data to the memory array of the one memory device when the second command ID number is equal to the second ID number and the write command is received at the second port,   wherein, when the first command ID number and the second command ID number both correspond to respective ones of the first and second ID numbers of the one memory device, writing the write data to the memory array and transferring the read data from the memory array are performed concurrently.