Fifo example figure 7.1a – Rainbow Electronics DS3134 User Manual

Page 87

DS3134

87 of 203

Starting Block Pointer. The Block Pointer RAM tells the device how to link the eight Blocks together to
form a circular chain.

The Host must set the Water Marks for the receive and transmit paths. The receive path has a High Water
Mark and the transmit path has a Low Water Mark.

FIFO Example Figure 7.1A

CH 1

CH 2

CH 3

CH 4

CH 5

CH 6

CH 7

CH 8

CH 9

CH 10

CH 11

CH 12

CH 13

CH 14

CH 15

CH 16

CH 17

CH 18

CH 19

CH 20

CH 21

CH 255

CH 256

not used

Block 0

Block 1

Block 2

Block 3

Block 4

Block 5

Block 6

Block 112

Block 113

Block 114

Block 115

Block 116

Block 117

Block 118

Block 119

Block 120

Block 121

Block 122

Block 123

Block 124

Block 125

Block 126

Block 127

Block 1022

Block 1023

not used

Channel 2

not used

Channel 16

Channel 6

Channel 2

Block 0

Block 1

Block 2

Block 3

Block 4

Block 5

Block 6

Block 4

Block 5

Block 3

Block 2

Block 114

Block 113

Block 119

Block 120

Block 121

Block 122

Block 125

Block 126

Block 112

Block 1022

Block 1023

Block 121

Block 122

Block 123

Block 124

Block 125

Block 126

Block 127

Block 112

Block 113

Block 114

Block 115

Block 116

Block 117

Block 118

Block 119

Block 120

1024 Block FIFO
(1 Block = 4 dwords)

Block Pointer
RAM

Starting Block
Pointer

Block Pointer 113

Block Pointer 5

Block Pointer 125

fifobd.drw

HDLC
Channel
Number

not used

Block 118

not used