GE 90-30/20/Micro manual Power-Up Sequence

2

*Go to Clear All Process

START

a45680

1

HHP

TRUE

*

CLEAR

CLR

M

T

ALL

KEYS

FALSE

2

TRUE

USD

FALSE

PRESENT AND

VALID

3

4

USD

FALSE

URAM

FALSE

PRG SRC =

PRG SRC =

PROM

PROM

TRUE

TRUE

11

URAM

TRUE

*CLEAR

CORRUPT

ALL

5

USD

FALSE

TRUE

FALSE

REG SRC =

12

13

PROM

URAM

TRUE

USD

TRUE

PRG SRC =

NOT PRESENT

PROM

6

7

FALSE

FALSE

HHP

TRUE

TRUE

HHP

LD

NOT

STOP MODE

LD

NOT

KEYS

KEYS

FALSE

9

FALSE

14

HHP

TRUE

8

COPY PRG ,CFG,

COPY

NOT RUN

STOP MODE

KEYS

& REGS FROM

PRG & CFG FROM

USD TO URAM

USD TO URAM

FALSE

15

URAM

TRUE

PU MODE =

RUN MODE

10

RUN

PRG or CFG

FALSE

CHECKSUM

FALSE

BAD

TRUE

*CLEARALL

Clear All Process

CLEAR ALL

19

CLEAR PRG, CFG,

AND REGS

STOP MODE

16

TRUE

LOW BATT STOP MODE

FALSE

17

URAM	TRUE
PU MODE =
	STOP MODE
STOP

18FALSE

PU MODE IS SAME,

AS POWERDOWN

STOP MODE END RUN MODE

Figure 2-5. Power-Up Sequence

Prior to the START statement on the Power Up Flowchart, the CPU goes through power up diagnostics which test various periphal devices used by the CPU and tests RAM. After completing diagnostics, internal data structures and periphal devices used by the CPU get initialized. The CPU then determines if User Ram has been corrupted. If User Ram is corrupted the user program and configuration are cleared out and defaulted and all user registers are cleared.

GFK-0467K Chapter 2 System Operation 2-31