diff --git a/src/hei_isolation_data.hpp b/src/hei_isolation_data.hpp
index fbebc87..b20f629 100644
--- a/src/hei_isolation_data.hpp
+++ b/src/hei_isolation_data.hpp
@@ -138,9 +138,8 @@
     bool queryCheckstop() const
     {
         auto itr = std::find_if(
-            iv_sigList.begin(), iv_sigList.end(), [](const auto& s) {
-                return ATTN_TYPE_CHECKSTOP == s.getAttnType();
-            });
+            iv_sigList.begin(), iv_sigList.end(),
+            [](const auto& s) { return ATTN_TYPE_CHIP_CS == s.getAttnType(); });
 
         return iv_sigList.end() != itr;
     }
diff --git a/src/hei_signature.hpp b/src/hei_signature.hpp
index dbf63a8..0cb0444 100644
--- a/src/hei_signature.hpp
+++ b/src/hei_signature.hpp
@@ -56,7 +56,7 @@
     BitPosition_t iv_bit   = 0; ///< Target bit within this register.
 
     /** Attention type reported by this bit. */
-    AttentionType_t iv_attnType = ATTN_TYPE_CHECKSTOP;
+    AttentionType_t iv_attnType = ATTN_TYPE_CHIP_CS;
 
   public: // Member functions
     /** @return The chip containing this register. */
diff --git a/src/hei_types.hpp b/src/hei_types.hpp
index 530481a..bdbbffb 100644
--- a/src/hei_types.hpp
+++ b/src/hei_types.hpp
@@ -167,21 +167,37 @@
     // clang-format off
 
     /** System checkstop hardware attention. Unrecoverable, fatal error. */
+    // TODO: This is deprecated and will be removed. Use CHIP_CS instead.
     ATTN_TYPE_CHECKSTOP   = 1,
 
-    /** Unit checkstop hardware attention. A unit within the system is no longer
-     *  usable but the rest of the system should be able to recover. */
+    /**
+     * Hardware error event indicating that an entire chip has checkstopped and
+     * is no longer usable.
+     */
+    ATTN_TYPE_CHIP_CS     = 1,
+
+    /**
+     * Hardware error event indicating that a unit within a chip has
+     * checkstopped and is no longer usable. Other units within the chip should
+     * continue uninterrupted. Possible degraded functionality.
+     */
     ATTN_TYPE_UNIT_CS     = 2,
 
-    /** Recoverable hardware attention. The system should be able to continue
-     *  uninterrupted, possible degraded functionality. */
+    /**
+     * Hardware error event in which the hardware recovered. The system should
+     * be able to continue uninterrupted. Possible degraded functionality.
+     */
     ATTN_TYPE_RECOVERABLE = 3,
 
-    /** Software or hardware event requiring action by the service processor
-     *  firmware. */
+    /**
+     * Software or hardware event requiring action by the service processor
+     * firmware.
+     */
     ATTN_TYPE_SP_ATTN     = 4,
 
-    /** Software or hardware event requiring action by the host firmware. */
+    /**
+     * Software or hardware event requiring action by the host firmware.
+     */
     ATTN_TYPE_HOST_ATTN   = 5,
 
     // clang-format on
diff --git a/test/simulator/testcases/eq_core_fir.cpp b/test/simulator/testcases/eq_core_fir.cpp
index 242d818..c7fa4f1 100644
--- a/test/simulator/testcases/eq_core_fir.cpp
+++ b/test/simulator/testcases/eq_core_fir.cpp
@@ -27,9 +27,9 @@
 REG_SCOM(proc0, 0x27024447, 0xBDDC26C5FE1300CC) // EQ_CORE_FIR_ACT1
 REG_SCOM(proc0, 0x27024448, 0x0000000000000080) // EQ_CORE_FIR_WOF
 
-EXP_SIG(proc0, 0x682c, 28, 1, CHECKSTOP)
-EXP_SIG(proc0, 0x682c, 28, 26, CHECKSTOP)
-EXP_SIG(proc0, 0x682c, 29, 63, CHECKSTOP)
+EXP_SIG(proc0, 0x682c, 28, 1, CHIP_CS)
+EXP_SIG(proc0, 0x682c, 28, 26, CHIP_CS)
+EXP_SIG(proc0, 0x682c, 29, 63, CHIP_CS)
 EXP_SIG(proc0, 0x682c, 28, 56, RECOVERABLE)
 EXP_SIG(proc0, 0x682c, 29, 56, RECOVERABLE)
 
diff --git a/test/simulator/testcases/sample_test_case.cpp b/test/simulator/testcases/sample_test_case.cpp
index 91fff43..0378fbd 100644
--- a/test/simulator/testcases/sample_test_case.cpp
+++ b/test/simulator/testcases/sample_test_case.cpp
@@ -68,27 +68,27 @@
 REG_SCOM(proc0, 0x0000f207, 0x5000000000000000) // LFIR2_ACT1 inst 0
 
 // LFIR0
-EXP_SIG(proc0, 0xa776, 0, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa776, 0, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa776, 0, 1, RECOVERABLE)
-EXP_SIG(proc0, 0xa776, 1, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa776, 1, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa776, 1, 1, RECOVERABLE)
 
 // LFIR1
-EXP_SIG(proc0, 0xa876, 0, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa876, 0, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa876, 0, 1, RECOVERABLE)
-EXP_SIG(proc0, 0xa876, 1, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa876, 1, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa876, 1, 1, RECOVERABLE)
-EXP_SIG(proc0, 0xa876, 2, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa876, 2, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa876, 2, 1, RECOVERABLE)
-EXP_SIG(proc0, 0xa876, 3, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa876, 3, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa876, 3, 1, RECOVERABLE)
-EXP_SIG(proc0, 0xa876, 4, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa876, 4, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa876, 4, 1, RECOVERABLE)
-EXP_SIG(proc0, 0xa876, 5, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa876, 5, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa876, 5, 1, RECOVERABLE)
 
 // LFIR2
-EXP_SIG(proc0, 0xa976, 0, 0, CHECKSTOP)
+EXP_SIG(proc0, 0xa976, 0, 0, CHIP_CS)
 EXP_SIG(proc0, 0xa976, 0, 1, RECOVERABLE)
 
 END_ITERATION
diff --git a/test/simulator/testcases/tod_fault.cpp b/test/simulator/testcases/tod_fault.cpp
index 1d03883..cebf4f3 100644
--- a/test/simulator/testcases/tod_fault.cpp
+++ b/test/simulator/testcases/tod_fault.cpp
@@ -18,7 +18,7 @@
 REG_SCOM(proc0, 0x00040032, 0xc000000000000000) // TOD_ERROR_MASK
 REG_SCOM(proc0, 0x00040033, 0xa000000000000000) // TOD_ERROR_ROUTING
 
-EXP_SIG(proc0, 0x7d9b, 0, 3, CHECKSTOP)
+EXP_SIG(proc0, 0x7d9b, 0, 3, CHIP_CS)
 EXP_SIG(proc0, 0xdf2a, 0, 26, RECOVERABLE)
 
 END_ITERATION