GMAC Credit-Based Shaping IdleSlope Register for Queue B
Credit-based shaping must be disabled in the GMAC_CBSCR before updating this register.
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| IS[31:24] | |||||||||
| Access | |||||||||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| IS[23:16] | |||||||||
| Access | |||||||||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| IS[15:8] | |||||||||
| Access | |||||||||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| IS[7:0] | |||||||||
| Access | |||||||||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
IdleSlope
IdleSlope value for queue B in bytes/second.
The IdleSlope value is defined as the rate of change of credit when a packet is waiting to be sent. This must not exceed the port transmit rate which is dependent on the speed of operation, e.g., 100 Mb/second = 32'h017D7840.
If 50% of bandwidth was to be allocated to a particular queue in 100 Mb/sec mode, then the IdleSlope value for that queue would be calculated as 32'h017D7840 / 2