C167CS datasheet(311/517 Pages) INFINEON

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C167CS

Derivatives

The Bootstrap Loader

User’s Manual

15-1

V2.0, 2000-07

The Bootstrap Loader

The built-in bootstrap loader of the C167CS provides a mechanism to load the startup

program, which is executed after reset, via the serial interface. In this case no external

memory or an internal ROM/OTP/Flash is required for the initialization code.

The bootstrap loader moves code/data into the internal RAM, but it is also possible to

transfer data via the serial interface into an external RAM using a second level loader

routine. ROM memory (internal or external) is not necessary. However, it may be used

to provide lookup tables or may provide “core-code”, i.e. a set of general purpose

subroutines, e.g. for IO operations, number crunching, system initialization, etc.

Figure 15-1

Bootstrap Loader Sequence

The Bootstrap Loader may be used to load the complete application software into

ROMless systems, it may load temporary software into complete systems for testing or

calibration, it may also be used to load a programming routine for Flash devices.

The BSL mechanism may be used for standard system startup as well as only for special

occasions like system maintenance (firmware update) or end-of-line programming or testing.

MCT04465

RSTIN

P0L.4

or RD

RxD0

TxD0

CSP:IP

32 bytes

User Software

Int. Boot ROM BSL-routine

1) BSL initialization time, > 2 µs @ f

CPU = 20 MHz.

2) Zero byte (1 start Bit, eight '0' data Bits, 1 stop Bit), sent by host.

3) Identification byte, sent by C 167CS.

4) 32 bytes of code / data, sent by host.

5) Caution: TxD0 is only driven a certain time after reception of the zero byte

(2.5 µs @

CPU = 20 MHz)

6) Internal Boot ROM.

C167CS Datasheet(PDF) 311 Page - Infineon Technologies AG