diff --git a/docs/spack_instructions.md b/docs/spack_instructions.md
index 9bd6d7f..1424a25 100644
--- a/docs/spack_instructions.md
+++ b/docs/spack_instructions.md
@@ -181,3 +181,19 @@
 # Example 1:  OneAPI-DPCPP implementation 
  $ spack install babelstream +sycl2020 implementation=ONEAPI-DPCPP
 ```
+## ACC
+* Target device selection process is automatic with 2 options:
+    * **gpu** : Globally set the target device to an NVIDIA GPU automatically if `cuda_arch` is specified 
+    * **multicore** : Globally set the target device to the host CPU automatically if `cpu_arch` is specified 
+
+| Flag        | Definition                      | 
+|-----------| ----------------------------------|
+| cuda_arch     |- List of supported compute capabilities are provided [here](https://github.com/spack/spack/blob/0f271883831bec6da3fc64c92eb1805c39a9f09a/lib/spack/spack/build_systems/cuda.py#LL19C1-L47C6) <br />- Useful [link](https://arnon.dk/matching-sm-architectures-arch-and-gencode-for-various-nvidia-cards/) for matching CUDA gencodes with NVIDIA architectures| 
+| CPU_ARCH   | This sets the `-tp` (target processor) flag, possible values are: <br /> `px`          - Generic x86 Processor <br /> `bulldozer`   - AMD Bulldozer processor <br /> `piledriver`  - AMD Piledriver processor <br /> `zen`         - AMD Zen architecture (Epyc, Ryzen) <br /> `zen2`        - AMD Zen 2 architecture (Ryzen 2) <br />  `sandybridge` - Intel SandyBridge processor <br /> `haswell`     - Intel Haswell processor <br /> `knl`         - Intel Knights Landing processor <br /> `skylake`     - Intel Skylake Xeon processor <br /> `host`        - Link native version of HPC SDK cpu math library <br /> `native`      - Alias for -tp host | `cpu_arch=skylake` |
+```shell
+# Example 1:  For GPU Run 
+ $ spack install babelstream +acc cuda_arch=<70>
+
+# Example 2:  For Multicore CPU Run 
+ $ spack install babelstream +acc cpu_arch=<bulldozer>
+```
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