HC4GX15 Datasheet, PDF (419/668 Pages) Altera Corporation – HardCopy IV Device Handbook

Chapter 1: HardCopy IV GX Transceiver Architecture
Functional Modes
1–155
XGMII-To-PCS Code Conversion at the Transmitter
In XAUI mode, the 8B/10B encoder in the HardCopy IV GX transmitter datapath is
controlled by a transmitter state machine that maps various 8-bit XGMII codes to
10-bit PCS code groups. This state machine complies with the IEEE P802.3ae PCS
transmit source state diagram shown in Figure 1–124.
Figure 1–124. XGMII-To-PCS Code Conversion in XAUI Mode (Note 1)
!reset
!(TX=||IDLE|| + TX=||Q||
SEND_Q
IF TX=||T|| THEN cvtx_terminate
tx_code_group<39:0> ⇐
ENCODE(TX)
PUDR
next_ifg = A_CNT≠0
(next_ifg + A_CNT≠0)
SEND_A
tx_code_group<39:0> ⇐ ||A||
next_ifg ⇐ K
PUDR
Q_det
!Q_det
SEND_Q
tx_code_group<39:0> ⇐ TQMSG
Q_det ⇐ K
PUDR
UCT
A_CNT≠0 *
B cod_sel=1
SEND_RANDOM_R
tx_code_group<39:0> ⇐ ||R||
A_CNT≠0 *
cod_sel=1 A
reset
SEND_K
tx_code_group<39:0> ⇐ ||K||
next_ifg ⇐ A
PUDR
UCT
B
A
SEND_RANDOM_K
tx_code_group<39:0> ⇐ ||K||
PUDR
A_CNT≠0 *
cod_sel=1
B
A_CNT=0
A_CNT=0
SEND_RANDOM_A
tx_code_group<39:0> ⇐ ||A||
PUDR
Q_det
A ^{A_CNT≠0 *}
cod_sel=1
SEND_RANDOM_Q
tx_code_group<39:0> ⇐ TQMSG
Q_det ⇐ FALSE
PUDR
B ^{!Q_det *}
cod_sel=1
A ^{!Q_det *}
cod_set=1
B ^cod_set=1
A ^cod_set=1
Note to Figure 1–124:
(1) This figure is from IEEE P802.3ae.
© June 2009 Altera Corporation
HardCopy IV Device Handbook Volume 3