STLC5466 datasheet(71/130 Pages) STMICROELECTRONICS

71 / 130 page

71/130

STLC5466

VII - EXTERNAL REGISTERS

These registers are located in shared memory. Initiate Block Address Registers (IBAR1 and IBAR2) give

respectively the Initiate Block Address (IBA1 and IBA2) in shared memory.

From IBA1 the different addresses are obtained:

• Initialization Block address concerning the first HDLC Controller (HDLC1)

• HDLC interrupt Queue for the first HDLC Controller (HDLC1) and the second (HDLC2)

• MON interrupt Queue

• C/I interrupt Queue

From IBA1 only the following address is obtained:

• Initialization Block address concerning the second HDLC Controller (HDLC2)

‘Not used’ bits (Nu) are accessible by the microprocessor but the use of these bits by software is not rec-

ommended.

VII.1 - Initialization Block in External Memory (IBA1 and IBA2)

When Direct Memory Access Controller receives START from one of 64 channels, it reads initialization

block immediately to know the first address of the first descriptor for this channel.

Bit 0 of Transmit Descriptor Address (TDA Low) and bit 0 of Receive Descriptor Address (RDA Low), are

at ZERO mandatory. This Least Significant Bit is not used by DMA Controller, the shared memory is al-

ways a 16 bit memory for the DMA Controller.

The Receive Descriptor Address (RDA) is never modified by the RX DMA Controller in this Initialization

Block

N.B. If several descriptors are used to transmit the current frame then before transmitting frame, TX DMA

Controller stores the address of the first Transmit Descriptor Address (TDA) into this Initialization Block if

BOF bit is at “1” (See Transmit Descriptor).

Descriptor Address

Channel

Address

bit15

bit8

bit7

bit0

CH 0

IBA+00

Not used

TDA High

IBA+02

Transmit Descriptor Address (TDA Low)

IBA+04

Not used

RDA High

IBA+06

Receive Descriptor Address (RDA Low)

CH1

IBA+08

Not used

TDA High

IBA+10

Transmit Descriptor Address (TDA Low)

IBA+12

Not used

RDA High

IBA+14

Receive Descriptor Address (RDA Low)

CH 2

CH30

IBA+16

IBA+246

CH 31

IBA+248

Not used

TDA High

IBA+250

Transmit Descriptor Address (TDA Low)

IBA+252

Not used

RDA High

IBA+254

Receive Descriptor Address (RDA Low)

STLC5466 Fiches technique(PDF) 71 Page - STMicroelectronics

STLC5466 Fiches technique(HTML) 71 Page - STMicroelectronics

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 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Fiches technique Télécharger

Lien URL