| 摘要 |
PROBLEM TO BE SOLVED: To improve the debug efficiency of a device driver which operates a fast plotting circuit and the debug efficiency of a fast plotting circuit hardware by comparing a plotting address outputted from the fast plotting circuit to a frame buffer with a stop address of a stop address register and holding the comparison result. SOLUTION: A CPU 3 issues a plot instruction to a fast plotting circuit 8. A comparator circuit 10 of a debug circuit 11 latches a memory address to a frame buffer 2 with a latch circuit 14 in a data write signal outputted by the circuit 8 to memory and compares it with the value of a stop address register 12 that stores a comparison address. A flag (address coincidence flag) 16 which shows a result of comparison performed by the circuit 10 is stored in a status register 13 and can be referred to. This makes it easier to confirm a circuit state at the time of illegal plotting, which therefore, helps make debug work efficient. |
