Lpc2000

Why is external memory boot is disabled when CRP is active.  Is this
because code in external memory can always read flash no matter what?

Does this mean that if you need CRP you cannot have external memory?

--- In lpc2000@yahoogroups.com, "Joel Winarske" <joelw@i...> wrote:
> User Manual excerpt:
> 
> Code Read Protection (CRP)
> --------------------------
> Code read protection is enabled by programming the flash address
location
> 0x1FC (User flash sector 0) with value 0x8765 4321 (2271560481 Decimal).
> Address 0x1FC is used to allow some room for the FIQ exception
handler. When
> the code read protection is enabled the JTAG debug port, external memory
> boot and the following ISP commands are disabled:
> . Read Memory
> . Write to RAM
> . Go
> . Copy RAM to Flash
> The ISP commands mentioned above terminate with return code
> CODE_READ_PROTECTION_ENABLED. The ISP erase command only allows erasure
> of all user sectors when the code read protection is enabled. This
> limitation does not exist if the code read protection is not
enabled. IAP
> commands are not affected by the code read protection.
>