SPRUJF8 May 2026 TMS320F28P551SG
On this device, the Input X-BAR is used to route signals from a GPIO to many different IP blocks such as the ADC, eCAP, ePWM, and external interrupts. The input of each Input X-BAR instance (INPUTx) can be any GPIO , while the output of each instance connects to various IP blocks in the device. The digital input of AIOs are also available as inputs to the Input X-BAR. This flexibility relieves some of the constraints on peripheral muxing by allowing the user to connect any GPIO to the specified outputs of each Input X-BAR instance. Note that the GPIO selected by the Input X-BAR can be configured as either an input or an output. The Input X-BAR simply connects the signal on the input buffer to the output of the selected Input X-BAR instance. Therefore, you can do things such as route the output of an ePWM to the eCAP module for a frequency test).
The Input X-BAR is configured by way of the INPUTxSELECT registers. The destinations for each INPUTx are shown in Figure 10-1 and Table 10-1. For additional details on how each Input X-BAR connects to other IP blocks throughout the device, look for references to Input X-BAR in the chapter associated with that IP. Note that the destinations of each INPUTx are fixed and are not user-configurable. For more information on configuring the Input X-BAR, see the INPUT_XBAR_REGS register definitions in the XBAR Registers section.
The minimum input pulse width required for ePWM, CLB XBAR (CLB Clocks required), SYSCLK for Output XBAR, and CLB Output XBAR is 3 ticks of the respective clocks.
| Input | ECAP | EPWM XBAR | CLB XBAR | OUTPUT XBAR | EPWM TRIP | ERAD | CMPSS | DCCx | CPU XINT | EPG | ADC SOC | EPWM / ECAP SYNC |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| INPUTXBAR1 | Yes | Yes | Yes | Yes | TZ1, TRIP1 | Yes | ||||||
| INPUTXBAR2 | Yes | Yes | Yes | Yes | TZ2, TRIP2 | Yes | ||||||
| INPUTXBAR3 | Yes | Yes | Yes | Yes | TZ3, TRIP3 | Yes | ||||||
| INPUTXBAR4 | Yes | Yes | Yes | Yes | Yes | XINT1 | ||||||
| INPUTXBAR5 | Yes | Yes | Yes | Yes | Yes | XINT2 | ADCEXTSOC | EXTSYNCIN1 | ||||
| INPUTXBAR6 | Yes | Yes | Yes | Yes | TRIP6 | Yes | XINT3 | EXTSYNCIN2 | ||||
| INPUTXBAR7 | Yes | Yes | Yes | Yes | CMPSS1/3. EXT_FILTIN_H | |||||||
| INPUTXBAR8 | Yes | Yes | Yes | Yes | CMPSS1/3. EXT_FILTIN_L | |||||||
| INPUTXBAR9 | Yes | Yes | Yes | Yes | CMPSS2/4. EXT_FILTIN_H | |||||||
| INPUTXBAR10 | Yes | Yes | Yes | Yes | CMPSS2/4. EXT_FILTIN_L | |||||||
| INPUTXBAR11 | Yes | Yes | Yes | Yes | CLK1 | |||||||
| INPUTXBAR12 | Yes | Yes | Yes | Yes | CLK1 | |||||||
| INPUTXBAR13 | Yes | Yes | Yes | Yes | XINT4 | EPGAIN1 | ||||||
| INPUTXBAR14 | Yes | Yes | Yes | Yes | XINT5 | EPGAIN2 | ||||||
| INPUTXBAR15 | Yes | Yes | CLK1 | EPGAIN3 | ||||||||
| INPUTXBAR16 | Yes | Yes | CLK0 | EPGAIN4 |