Using Hardware Trace to Single Instruction Step Through a User Program
Original Publication Date: 1985-May-01
Included in the Prior Art Database: 2005-Feb-18
A technique is described whereby users of the IBM Series/1 will have the ability to single-step through a program by using a trace program, thereby enhancing the testing and debugging of users' programs. It also eliminates the need to stop the Series/1 or to set stops at the console. The use of the hardware trace program allows a user call 1 to enter debug 2 after execution of every instruction. When a single step (SS) 3 command is given, a jump is loaded in the interrupt handler 4 and the Level Status Register (LSR) bit 10 is set on, thereby putting the processor into hardware trace mode. Command options allow a specified number of commands to be executed before control is returned to the user through debug 2.