CC2430 Datasheet, PDF (63/234 Pages) Texas Instruments – A True System-on-Chip solution for 2.4 GHz IEEE 802.15.4 / ZigBee-TM

CC2430
12.9.2 Debug Communication
The debug interface uses an SPI-like two-wire
interface consisting of the Debug Data (P2_1)
and Debug Clock (P2_2) pins. Data is driven
on the bi-directional Debug Data pin at the
positive edge of Debug Clock and data is
sampled on the negative edge of this clock.
Debug commands are sent by an external host
and consist of 1 to 4 output bytes (including
command byte) from the host and an optional
input byte read by the host. Figure 16 shows a
timing diagram of data on the debug interface.
The first byte of the debug command is a
command byte and is encoded as follows:
• bits 7 to 3 : instruction code
• bits 2
: return input byte to host byte
when high
• bits 1 to 0 : number of output bytes from
host following instruction code
byte
P2_2
P2_1
command
first data byte
second data byte
host input byte
Figure 16: Debug interface timing diagram
12.9.3 Debug Commands
The debug commands are shown in Table 33.
Some of the debug commands are described
in further detail in the following sections.
12.9.4 Debug Lock Bit
For software code security the Debug Interface
may be locked. When the Debug Lock bit ,
DBGLOCK, is set (see section 13.14.3) all debug
commands
except
CHIP_ERASE,
READ_STATUS and GET_CHIP_ID are
disabled and will not function. The status of
the Debug Lock bit can read using the
READ_STATUS command (see section
12.9.6). Note that when the Debug Lock bit
has been set, and before reset of the device,
the Debug Lock value returned by
READ_STATUS will only represent the actual
Debug Lock value once either a HALT,
RESUME, DEBUG_INSTR or STEP command
has been attempted executed.
The CHIP_ERASE command is used to clear
the Debug Lock bit.
12.9.5 Debug Configuration
The commands WR_CONFIG and
RD_CONFIG are used to access the debug
configuration data byte. The format and
description of this configuration data is shown
in Table 34.
12.9.6 Debug Status
A Debug status byte is read using the
READ_STATUS command. The format and
description of this debug status is shown in
Table 35.
The READ_STATUS command is used e.g. for
polling the status of flash chip erase after a
CHIP_ERASE command or oscillator stable
status required for debug commands HALT,
RESUME, DEBUG_INSTR, STEP_REPLACE
and STEP_INSTR.
CC2430 PRELIMINARY Data Sheet (rev. 1.03) SWRS036A
Page 63 of 232