Referencing-in-Array Scheme for RRAM-based CIM Architecture
Abhairaj Singh1,a, Rajendra Bishnoi1,b, Rajiv V. Joshi2 and Said Hamdioui1,c
1Computer Engineering Laboratory, TU Delft, The Netherlands
aa.singh-5@tudelft.nl
br.k.bishnoi@tudelft.nl
cs.hamdioui@tudelft.nl
2IBM Thomas J. Watson Research Centre, Yorktown Heights, NY 10598 USA
rvjoshi@ibm.us
ABSTRACT
Resistive random access memory (RRAM) based computation-in-memory (CIM) architectures are attracting a lot of attention due to their potential in performing fast and energyefficient computing. However, the RRAM variability and nonidealities limit the computing accuracy of such architectures, especially for multi-operand logic operations. This paper proposes a voltage-based differential referencing-in-array scheme that enables accurate two and multi-operand logic operations for RRAM-based CIM architecture. The scheme makes use of a 2T2R cell configuration to create a complementary bitcell structure that inherently acts also as a reference during the operation execution; this results in a high sensing margin. Moreover, the variation-sensitive multi-operand (N)AND operation is implemented using complementary-input (N)OR operation to further improve its accuracy. Simulation results for a post-layout extracted 512x512 (256Kb) RRAM-based CIM array show that up to 56 operand (N)OR/(N)AND operation can be accurately and reliably performed as opposed to a maximum of 4 operands supported by state-of-the-art solutions, while offering up to 11.4X better energy-efficiency.
