mt90503 Zarlink Semiconductor, mt90503 Datasheet - Page 54

• Manufacturer Part Number: mt90503
• Description: 2048vc Aal1 Sar
• Manufacturer: Zarlink Semiconductor

Figure 20 TDM Circular Buffer (Complete Buffer in E1 mode, FASTCAS) is an E1 circular buffer in the FASTCAS
mode. Although the TDM read and write pointers are still significantly offset, the delay has been reduced to nearly
zero. This is because the rx_sar_write_pnt and the TDM_read_pnt need only be offset by a single byte, as in
non-multiframing mode.
tx_sar_read_pnt
tdm_write_pn
t (earliest)
tdm_cas_write_p
nt (earliest)
tdm_write_pn
t (latest)
tdm_cas_write_p
nt (latest)
Figure 20 - TDM Circular Buffer (Complete Buffer in E1 mode, FASTCAS)
15 byte offset
n=Buffer word size {128,256,512,1024}
+(n*2)-40
+(n*2)-20
+20
+40
+60
+80
+0
b 15
b14
TX MultiFrame (n/32)-2
TX MultiFrame (n/32)-1
Reserved
T X MultiFrame 0
TX MultiFrame 1
TX MultiFrame 2
TX MultiFrame 3
TX MultiFrame 4
b13
High byte
b12
b11
Zarlink Semiconductor Inc.
b10
MT90503
b9
b8
54
b7
b6
RX MultiFrame (n/32)-2
RX MultiFrame (n/32)-1
RX MultiFrame 0
RX MultiFrame 1
RX MultiFrame 2
RX MultiFrame 3
RX MultiFrame 4
b5
Valid rx_sar_write_pnt Positions
Valid tx_sar_read_pnt Positions
Low byte
b4
b3
b2
b1
b0
tdm _cas_read_pnt
tdm _read_pnt
rx_sar_write_pnt
2 MF offset
1 byte offset
MINIMUM
Data Sheet