DB929B datasheet(38/51 Pages) CMLMICRO

38 / 51 page

4-Level FSK Modem Data Pump

Page 38 of 50

MX929B PRELIMINARY INFORMATION

www.mxcom.com Tel: 800 638 5577 336 744 5050

Fax: 336 744 5054

Doc. # 20480171.003

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA

All trademarks and service marks are held by their respective companies.

Value of µC variable 'STATE' on entry to IRQ routine

and corresponding MX929B's actions:

0 : Frame Sync has been recognized

and Station ID block received,

read out data and load RHB task.

1 : Header block has been received,

read out data and load RILB task.

2 : Intermediate block has been received,

read out data and load RILB task.

3 : Last block has been received,

read out data and finish.

Read Status Register

Yes

START

( IRQ line goes low )

RETURN

( Not MX929B IRQ )

IRQ bit = 1 ?

BFREE bit = 1 ?

DIBOVF bit = 0 ?

'STATE' = 0 ?

'STATE' = 1 ?

'STATE' = 2 ?

CRCERR bit = 0 ?

'IBLOCKS' = 0 ?

'STATE' = 3 ?

Set µC variable 'STATE' to 9

Set µC variable 'STATE' to 3

Decrement µC variable

'IBLOCKS'

RETURN

( Error )

Read 10 Header block bytes

from the Data Buffer then

write a RILB task to the

Command Register

Read 12 Intermediate Block

bytes from the Data Buffer

then write a RILB task to

the Command Register

Set µC variable 'IBLOCKS'

to the number of Intermediate

Blocks to be received

Read 8 Last Block data bytes

from the Data Buffer.

Increment µC variable

'STATE'

Read 3 Station ID bytes

from the Data Buffer

then write a RHB task to

the Command Register

Figure 22: Rx Interrupt Service routine

Note: This routine assumes that the number of Intermediate blocks in the Frame is contained within the

Header Block Data.

DB929B Datasheet(PDF) 38 Page - CML Microcircuits

DB929B Datasheet(HTML) 38 Page - CML Microcircuits

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

Datasheet Download

Link URL