SPRUIY2 November 2024 F29H850TU , F29H859TU-Q1
The ERAD Enhanced bus comparator (EBC) module bus comparator units that generate hardware watch points to the CPU by monitoring either the data read address bus or data write address bus.
A hardware watchpoint triggers a debug event when either an address or an address and data match a compare value. The address portion is compared against a reference address and bit mask, and the data portion is compared against a reference data value and a bit mask.
When comparing two addresses, you can set two watchpoints. When comparing an address and a data value, you can set only one watchpoint. When performing a read watchpoint, the address is available a few cycles earlier than the data; the watchpoint logic accounts for this.
The point where execution stops depends on whether the watchpoint was a read or write watchpoint, and whether the watchpoint was an address or an address/data read watchpoint. In the following example, a read address watchpoint occurs when the address X is accessed, and the CPU stops with the instruction counter (IC) pointing three instructions after that point.
For a read watchpoint that requires both an address and data match, the CPU stops with the IC pointing six instructions after that point.
In the following example, a write address watchpoint occurs when the address Y is accessed, and the CPU stops with the IC pointing six instructions after that point.