Rainbow Electronics DS3131 - Manual (Page 66)

DS3131
66 of 174
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 watermarks for the receive and transmit paths. The receive path has a high
watermark and the transmit path has a low watermark.
Figure 8-1. FIFO Example
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 39
CH 40
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 510
Block 511
not used
not used
not used
Channel 2
not used
not used
not used
not used
not used
not used
Channel 16
Channel 16
Channel 16
Channel 16
Channel 6
Channel 6
Channel 2
Channel 2
Channel 2
Channel 2
Channel 2
Channel 2
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 510
Block 511
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
512 Block FIFO
(1 Block = 4 dwords) Block Pointer
RAM Starting Block
Pointer
Block Pointer 113
Block Pointer 5
Block Pointer 125
bfifobd.drw
HDLC
Channel
Number
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used
Block 118
not used
not used
not used
not used
not used
not used
not used
not used
not used
not used