Datasheet

www.ti.com EMAC Control Module Registers
32.3.13 EMAC Control Module Transmit Interrupts Per Millisecond Registers (C0TXIMAX)
The EMAC control module transmit interrupts per millisecond register (C0TXIMAX) is shown in
Figure 32-24 and described in Table 32-23
Figure 32-24. EMAC Control Module Transmit Interrupts Per Millisecond Register (C0TXIMAX)
(offset = 74h)
31 16
Reserved
R-0
15 6 5 0
Reserved TXIMAX
R-0 R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 32-23. EMAC Control Module Transmit Interrupts Per Millisecond Register (C0TXIMAX)
Bit Field Value Description
31-6 Reserved 0 Reserved
5-0 TXIMAX 2-3Fh TXIMAX is the desired number of C0TXPULSE interrupts generated per millisecond when
C0TXPACEEN is enabled in INTCONTROL.
The pacing mechanism can be described by the following pseudo-code:
while(1) {
interrupt_count = 0;
/* Count interrupts over a 1ms window */
for(i = 0; i < INTCONTROL[INTPRESCALE]*250; i++) {
interrupt_count += NEW_INTERRUPT_EVENTS();
if(i < INTCONTROL[INTPRESCALE]*pace_counter)
BLOCK_EMAC_INTERRUPTS();
else
ALLOW_EMAC_INTERRUPTS();
}
ALLOW_EMAC_INTERRUPTS();
if(interrupt_count > 2*TXIMAX)
pace_counter = 255;
else if(interrupt_count > 1.5*TXIMAX)
pace_counter = previous_pace_counter*2 + 1;
else if(interrupt_count > 1.0*TXIMAX)
pace_counter = previous_pace_counter + 1;
else if(interrupt_count > 0.5*TXIMAX)
pace_counter = previous_pace_counter - 1;
else if(interrupt_count != 0)
pace_counter = previous_pace_counter/2;
else
pace_counter = 0;
previous_pace_counter = pace_counter;
}
1799
SPNU563–May 2014 EMAC/MDIO Module
Submit Documentation Feedback
Copyright © 2014, Texas Instruments Incorporated