3 CPU AND DEBUGGER
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
3-1
(Rev. 2.00)
3 CPU and Debugger
3.1 Overview
This IC incorporates a Cortex
®
-M0+ CPU core manufactured by Arm Ltd.
3.2 CPU Core
The following shows the system configuration of the Cortex
®
-M0+ CPU core embedded in this IC:
• Cortex
®
-M0+ core
• 32-bit single-cycle multiplier
• Nested vectored interrupt controller (NVIC)
• System timer (Systick)
• Serial-wire debug port (SW-DP)
• Micro trace buffer (MTB)
• Number of hardware break points: 4
• Number of watch points: 2
For detailed information on the Cortex
®
-M0+ CPU core, refer to the “Cortex
®
-M0+ Technical Reference Manual.”
3.3 Debugger
This IC includes a serial-wire debug port (SW-DP). For detailed information on the debug functions, refer to the
“Cortex
®
-M0+ Technical Reference Manual.”
3.3.1 List of Debugger Input/Output Pins
Table 3.3.3.1 lists the debug pins.
Table 3.3.1.1 List of Debug Pins
Pin name
I/O
Initial state
Function
SWCLK
O
O
On-chip debugger clock input pin
Input a clock from a debugging tool.
SWD
I/O
I
On-chip debugger data input/output pin
Used to input/output debugging data.
The debugger input/output pins are shared with general-purpose I/O ports and are initially set as the debug pins. If
the debugging function is not used, these pins can be switched to general-purpose I/O port pins. For details, refer to
the “I/O Ports” chapter.
3.3.2 External Connection
Figure 3.3.2.1 shows a connection example between this IC and a debugging tool when performing debugging.
SWCLK
SWD
SWCLK
SWD
V
DD
R
DBG1
R
DBG2
Debugging
tool
S1C31 MCU
Figure 3.3.2.1 External Connection
For the recommended pull-up resistor value, refer to “Recommended Operating Conditions, Debug pin pull-up re-
sistors R
DBG1–2
” in the “Electrical Characteristics” chapter. R
DBG1
and R
DBG2
are not required when using the debug
pins as general-purpose I/O port pins.