TWR-K20D72M User’s Manual
Page 8 of 17
VBAT supply. The holder can accept common 20mm diameter 3V lithium coin cell batteries (e.g. 2032,
2025). Refer to the description J13 in Table 4 “TWR-K20D72M Jumper Table” for more information.
2.4
Debug Interface
There are two debug interface options provided: the on-board OSJTAG circuit and an external Cortex
Debug connector.
2.4.1
OSJTAG
An on-board, MC9S08JM60 based Open Source BDM (OSBDM) circuit provides a debug interface to the
K20D72M. A standard USB A male to Mini-B male cable (provided) can be used for debugging via the
USB connector, J14. The OSJTAG interface also provides a USB to serial bridge. Drivers for the OSJTAG
interface are provided in the
P&E Micro Kinetis Tower Toolkit
(available on the included DVD).
2.4.2
Cortex Debug Connector
The Cortex Debug connector is a 20-pin (0.05") connector providing access to the SWD, SWV, JTAG,
cJTAG, EzPort signals available on the K20 device. The pinout and K20 pin connections to the debug
connector, J11, is shown in Table 1
Table 1.
Cortex Debug Connector Pinout
Pin
Function
TWR-K20D72M connection
1
VTref
MCU supply (MCU_PWR)
2
TMS/SWDIO
PTA3/UART0_RTS_b/FTM0_CH0/JTAG_MS/SWD_DIO
3
GND
GND
4
TCK/SWCLK
PTA0/UART0_CTS_b/FTM0_CH5/JTAG_CLK/SWD_CLK/EZP_CLK
5
GND
GND
6
TDO/SWO
PTA2/UART0_TX/FTM0_CH7/JTAG_DO/TRACE_SWO/EZP_DO
7
Key
-
8
TDI
PTA1/UART0_TX/FTM0_CH6/JTAG_DI/EZP_DI
9
GNDDetect
PTA4/FTM0_CH1/MS/NMI_b/EZP_CS_b
10
nReset
RESET_b
11
Target Power
5V supply (via J10)
12
-
-
13
Target Power
5V supply (via J10)
14
-
-
15
GND
GND
16
-
-
17
GND
GND
18
-
-
19
GND
GND
20
-
-
