Cyclone V Device Handbook: Volume 2: Transceivers

ID 683586
Date 10/24/2018
Public
Document Table of Contents

1.3.1.3.6. Encoder Output During Reset Sequence

When in reset (reset_tx_digital is high), a K28.5- (K28.5 10-bit code group from the RD– column) is sent continuously until reset_tx_digital is low. Because of some pipelining of the transmitter channel PCS, some “don’t cares” (10’hxxx) are sent before the three synchronizing K28.5 code groups. User data follows the third K28.5 code group.

Figure 27. 8B/10B Encoder Output During and After Reset Conditions8B/10B encoder output during and after reset conditions in both single- and double-width modes.
Table 14.  8B/10B Encoder Output During and After Reset Conditions
Operation Mode During 8B/10B Reset After 8B/10B Reset Release
Single Width Continuously sends the /K28.5/ code from the RD– column Some “don't cares” are seen due to pipelining in the transmitter channel, followed by three /K28.5/ codes with proper disparity—starts with negative disparity—before sending encoded 8-bit data at its input.
Double Width Continuously sends the /K28.5/ code from the RD– column on the LSByte and the /K28.5/ code from the RD+ column on the MSByte Some “don't cares” are seen due to pipelining in the transmitter channel, followed by:
  • Three /K28.5/ codes from the RD– column before sending encoded 8-bit data at its input on LSByte.
  • Three /K28.5/ codes from the RD+ column before sending encoded 8-bit data at its input on MSByte.