Cypress Semiconductor FX2LP Información técnica Pagina 96

  • Descarga
  • Añadir a mis manuales
  • Imprimir
  • Pagina
    / 460
  • Tabla de contenidos
  • MARCADORES
  • Valorado. / 5. Basado en revisión del cliente
Vista de pagina 95
EZ-USB FX2 Technical Reference Manual
Page 4-6 EZ-USB FX2 Technical Reference Manual v2.1
4.3 Interrupt Processing
When an enabled interrupt occurs, the FX2 completes the instruction it’s currently executing, then
vectors to the address of the interrupt service routine (ISR) associated with that interrupt (see
Table 4-9). The FX2 executes the ISR to completion unless another interrupt of higher priority
occurs. Each ISR ends with a RETI (return from interrupt) instruction. After executing the RETI,
the FX2 continues executing firmware at the instruction following the one which was executing
when the interrupt occurred.
The FX2 always completes the instruction in progress before servicing an interrupt. If the instruc-
tion in progress is RETI, or a write access to any of the IP, IE, EIP, or EIE SFRs, the FX2 com-
pletes one additional instruction before servicing the interrupt.
4.3.1 Interrupt Masking
The EA Bit in the IE SFR (IE.7) is a global enable for all interrupts except the RESUME (USB
wakeup) interrupt, which is always enabled. When EA = 1, each interrupt is enabled or masked by
its individual enable bit. When EA = 0, all interrupts are masked except the USB wakeup interrupt.
Table 4-9 provides a summary of interrupt sources, flags, enables, and priorities.
Vista de pagina 95
1 2 ... 91 92 93 94 95 96 97 98 99 100 101 ... 459 460

Comentarios a estos manuales

Sin comentarios