Strobes – Altera PHYLite User Manual

Page 28

Advertising
background image

Legend in

Figure 16

Description

2

Retrieve number of groups in the interface (cache once per interface)
• {id[3:0],24'h00E000} + {4'h0,pt_ptr[23:0]} + 4'h4

• You can skip this if it saved in the core during compilation (for example, hard

coded in RTL logic)

3

Retrieve group information (cache once per group)
• {id[3:0],24'h00E000} + {4'h0,pt_ptr[23:0]} + 24'h4 + grp_num

• Not always necessary

4

Retrieve Lane/Pin Address Offsets for group (cache once per group)
• {id[3:0],24'h00E000} + pt_ptr + {22'd0,num_grps[7:2],2'b00} + 28'd8

5

Perform lane/pin address translation (cache once per pin)
• {id[3:0],24'h00E000} + {12'h000,lane_ptr[15:0]} + lane_num

• {id[3:0],24'h00E000} + {12'h000,pin_ptr[15:0]} + {17'h0,pin_num[5:0], 1'b0}

6

Read/Write Avalon Calibration Bus
• {id[3:0],24'h800000} + read_from_step_4 + intra_lane_addr

Caching look-ups 1-4 (8-bytes of information) allows for pin and lane translations in one look-up.

Strobes

The first pins listed in the pin address look-up table are the strobes. They are also identified by

bits[7:4]

= 0xE

. For separate strobes, the input strobe is always first. For differential and complementary strobes,

the positive pin is the lower index.
Note: The output phase of differential strobes can be modified by writing to either the positive or

negative pin. Only one write is necessary. This is also the case for output only complementary

strobes.

28

Strobes

ug_altera_phylite

2015.01.16

Altera Corporation

Altera PHYLite for Parallel Interfaces IP Core User Guide

Send Feedback

Advertising