
24 On-chip Debugger (DBG)
S1C17003 TECHNICAL MANUAL
EPSON
24-3
DBG
24.3 Additional Debugging Function
The S1C17003 expands the following on-chip debugging functions of the S1C17 core.
Branching destination in debug mode
When a debug interrupt is generated, the S1C17 core enters debug mode and branches to the debug processing
routine. In this process, the S1C17 core is designed to branch to address 0xfffc00. In addition to this branching
destination, the S1C17003 also allows designation of address 0x0 (beginning address of internal RAM) as
the branching destination when debug mode is activated. The branching destination address is selected using
DBADR (D8/MISC_IRAMSZ register). When the DBADR is set to "0" (default), the branching destination is
set to 0xfffc00. When it is set to "1," the branching destination is set to 0x0.
DBADR: Debug Base Address Select Bit in the IRAM Size Select (MISC_IRAMSZ) Register (D8/0x5326)
Adding instruction breaks
The S1C17 core supports two instruction breaks (hardware PC breaks). The S1C17003 increased this number
to five, adding the control bits and registers given below.
IBE2: Instruction Break #2 Enable Bit in the Debug Control (DCR) Register (D5/0xffffa0)
IBE3: Instruction Break #3 Enable Bit in the Debug Control (DCR) Register (D6/0xffffa0)
IBE4: Instruction Break #4 Enable Bit in the Debug Control (DCR) Register (D7/0xffffa0)
IBAR2[23:0]: Instruction Break Address #2 Bits in the Instruction Break Address (IBAR2) Register 2
(D[23:0]/0xffffb8)
IBAR3[23:0]: Instruction Break Address #3 Bits in the Instruction Break Address (IBAR3) Register 3
(D[23:0]/0xffffbc)
IBAR4[23:0]: Instruction Break Address #4 Bits in the Instruction Break Address (IBAR4) Register 4
(D[23:0]/0xffffd0)
To use five hardware PC breaks (including four user breaks, and one reserved), the S1C17 Software Integrated
Development Environment GNU17 (ver. 1.2.1 or later) must be installed.