请教一下JLink能检测到但无法下载的原因？

[gress01]

用SW模式，可以检测到（用JTAG无法检测到），处理器是LPC1764（换的一片新的），错误信息如下：
JLink info:
------------
DLL: V4.15n, compiled Jun 18 2010 19:55:09
Firmware: J-Link ARM V8 compiled Jun 19 2012 11:29:30
Hardware: V8.00
S/N : 17892859
Feature(s) : RDI,FlashDL,FlashBP,JFlash

* JLink Info: Found SWD-DP with ID 0x2BA01477
**JLink Warning: No matching core found.
* JLink Info: SYSRESETREQ has confused core. Trying to reconnect and use VECTRESET.
* JLink Info: Found SWD-DP with ID 0x2BA01477
**JLink Warning: Failed to reset CPU. VECTRESET has confused core.
* JLink Info: CPU core locked up
* JLink Info: CPU halted
* JLink Info: Core is locked-up, trying to disable WDT.
* JLink Info: CPU core locked up
* JLink Info: CPU halted
* JLink Info: Core is locked-up, trying to disable WDT.
* JLink Info: CPU core locked up
* JLink Info: CPU halted
* JLink Info: CPU core locked up
* JLink Info: CPU halted
**JLink Warning: S_RESET_ST not cleared
* JLink Info: SYSRESETREQ has confused core. Trying to reconnect and use VECTRESET.
* JLink Info: Found SWD-DP with ID 0x2BA01477
**JLink Warning: Failed to reset CPU. VECTRESET has confused core.
* JLink Info: CPU core locked up
* JLink Info: CPU halted
* JLink Info: Core is locked-up, trying to disable WDT.
* JLink Info: CPU core locked up
* JLink Info: CPU halted
* JLink Info: Core is locked-up, trying to disable WDT.
* JLink Info: CPU core locked up
* JLink Info: CPU halted
* JLink Info: CPU core locked up
* JLink Info: CPU halted
**JLink Warning: S_RESET_ST not cleared
***JLink Error: Parity error (Data = 0x8AE8051F, ReceivedParity = 1)
ROMTableAddr = 0x0

Target info:
------------
Device: LPC1764
VTarget = 2.801V
State of Pins:
TCK: 0, TDI: 1, TDO: 0, TMS: 1, TRES: 1, TRST: 1
* JLink Info: Found SWD-DP with ID 0x2BA01477
**JLink Warning: No matching core found.
Hardware-Breakpoints: 0
Software-Breakpoints: 2048
Watchpoints: 0
JTAG speed: 1000 kHz

* JLink Info: Program size too small. Flash download skipped.
**JLink Warning: Could not read memory location 0x10000000 when trying to set soft RAM BP
Cannot setup Breakpoint at Address
**JLink Warning: Could not read memory location 0x10000000 when trying to set soft RAM BP
Cannot setup Breakpoint at Address
Erase Failed!
***JLink Error: Could not start CPU core. (ErrorCode: -1)