Address map – Meinberg VME31 User Manual

Page 9

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method is to read the clock interrupt driven or poll the 100th-of-seconds until the
value changes: in both of the cases, the software has an interval of 10ms to read the
desired data.

Address Map

The VME31 radio remote clock has a A16:D8 bus interface, so the dual port RAM
must be accessed byte wide on odd address offsets related to the base address. The
address map is shown below:

01h

(reserved)

03h

(reserved)

05h

interrupt vector (default: 0Fh)

07h

interrupt level (00h..07h, default: 00h - disabled)

09h

interrupt rate (default: 00h, see below)

0Bh

EPROM ID

0Dh

status (see below)

0Fh

year (00h..99h)

11h

month (01h..12h)

13h

day-of-month (01h..31h)

15h

hour (00h..23h)

17h

minute (00h..59h)

19h

second (00h..59h)

1Bh

sec100 (00h..99h)

1Dh

day-of-week (01h..07h, 01h = Monday)

1Fh

(reserved)

Date and time values are represented in packed BCD numbers.

The bits of the status byte are defined as described below:

bit

stands for

“1”

“0”

D0

clock´s current state:

free running

DCF77 controlled

D1

daylight saving:

enabled

disabled

D2

Sync´ed since last Reset:

yes

no

D3

dayl. saving going to change: yes

no

D4

interrupt

enabled

disabled

D5

(reserved, always "0")

D6

(reserved, always "0")

D7

on-board RTC time invalid:

yes

no

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