Low-Density Parity-Check (LDPC) codes have been adopted in the physical layer of many communication systems because of their superior performance. The direct implementation of these codes onto an existing software defined radio (SDR) platform is likely to be inefficient. Our approach is to design the LDPC code to match the constraints imposed by the existing architecture, with-out compromising the communication performance. We present a procedure for architecture-aware code design that involves feature identification, code construction and verification. Details of the procedure for the case when the SDR platform is equipped with a multi-stage interconnection network (MIN) is presented. By analyzing the characteristics of the MIN, simple yet explicit constraints are derived and used in the code construction step. The resulting LDPC code can not only be mapped very efficiently onto the SDR platform but also has very good bit error rate (BER) performance.