UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 742 o f 792
NXP Semiconductors UM10237
Chapter 33: LPC24XX EmbeddedICE
5. JTAG function select
Remark: JTAG access to the LPC2400 is only possible if no code read protection is
selected, see Section 3–5.
The JTAG port may be used either for debug or for boundary scan. The state of the
DBGEN pin determines which function is available. When DBGEN = 0, the JTAG port may
be used for boundary scan. When DBGEN = 1, the JTAG port may be used for debug.
6. Register description
The EmbeddedICE logic contains 16 registers as shown in Table33–679 below. The
ARM7TDMI-S debug architecture is described in detail in "ARM7TDMI-S (rev 4) T echnical
Reference Manual" (ARM DDI 0234A) published by ARM Limited.
7. Block diagram
The block diagram of the debug environment is shown below in Figure 33–147.
Table 679. Embe dded ICE logic registers
Name Width Description Address
Debug Control 6 Force debug state, disable interrupts 00000
Debug Status 5 Status of debug 00001
Debug Comms Control Register 32 Debug communication control register 00100
Debug Comms Data Register 32 Debug communication data register 00101
Watchpoint 0 Address Value 32 Holds watchpoint 0 address value 01000
Watchpoint 0 Address Mask 32 Holds watchpoint 0 address mask 01001
Watchpoint 0 Data Value 32 Holds watchpoint 0 data value 01010
Watchpoint 0 Data Mask 32 Holds watchpoint 0 data mask 01011
Watchpoint 0 Control Value 9 Holds watchpoint 0 control value 01100
Watchpoint 0 Control Mask 8 Holds watchpoint 0 control mask 01101
Watchpoint 1 Address Value 32 Holds watchpoint 1 address value 10000
Watchpoint 1 Address Mask 32 Holds watchpoint 1 address mask 10001
Watchpoint 1 Data Value 32 Holds watchpoint 1 data value 10010
Watchpoint 1 Data Mask 32 Holds watchpoint 1 data mask 10011
Watchpoint 1 Control Value 9 Holds watchpoint 1 control value 10100
Watchpoint 1 Control Mask 8 Holds watchpoint 1 control mask 10101