respectively. The code within the 604-byte download block pokes these bytes starting from address 0. That is, these instructions are placed into memory, one word at a time, as data. The following instructions are used.

mov

R1, #0A55Ah

; begin: DISWDT

mov

0, R1

 

 

mov

R1, #0A5A5h

 

 

mov

2, R1

 

 

mov

R1, #0B54Ah

;

EINIT

mov

4, R1

 

 

mov

R1, #0B5B5h

 

 

mov

6, R1

 

 

This pattern is used throughout sections 2 and 3. First the word is written to register R1. Then the register is copied to memory. The file BTL67.DAT contains the bytes downloaded to the RMB-167 board during bootstrapping. The file BTL.SRC contains the source code.

The initialization routines configure the SYSCON register. The internal ROM is disabled and the external bus is activated. Next the CSP and DPP registers are initialized. These steps need to be completed before the EINIT instruction. Note that if the watchdog timer is to be disabled; this too must be done before the EINIT instruction.

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RCA RMB-167 manual Mov R1, #0A55Ah