X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=interrupts%2Finterrupt_handling.mdwn;h=1af87d41cdc8614a820570cd7fec239218c70e48;hb=HEAD;hp=57cfed24da5a8b7590382bb4fe43e59e5dfb3d0f;hpb=1d9f60735abdb0a5a5c5bfc5c4a5da28bcb1034c;p=libreriscv.git diff --git a/interrupts/interrupt_handling.mdwn b/interrupts/interrupt_handling.mdwn deleted file mode 100644 index 57cfed24d..000000000 --- a/interrupts/interrupt_handling.mdwn +++ /dev/null @@ -1,34 +0,0 @@ -# Interrupt Handling in RISC-V - -This is a non-authoritative document for informally capturing the -requirements for interrupt handling across the spectrum of the entire -RISC-V ecosystem, with a view to finding common ground. Following on -from that will be seeing where collaboration is (and is not) feasible, -and, crucially, if the existing structures (such as the various PLIC -implementations that already exist) cover peoples' needs (or not). - -# Requirements Discussion - -This section is intended for capturing requirements from different sources -so that they can be viewed and compared in one place. If you are not -familiar with markdown or editing of wikis please contact -luke.leighton@gmail.com, sending the appropriate text, for inclusion here. - -* **Libre-RISCV Shakti M-Class**: a 300-400 pin SoC with almost a hundred - separate and distinct "slow" (below 160mhz) peripherals that need - nothing particularly special in the way of fast latency IRQs, just lots - of them. Five UARTs, each requiring one IRQ line; Four I2C peripherals, - each requiring two IRQ lines, Multiple Quad SPI interfaces requring - **six** IRQ lines (each!), and 32 "EINT" lines (general-purpose - external interrupt) which are intended for mundane purposes such as - "lid opened", or "volume key pressed" and "headphone jack inserted", - the number of IRQ lines required to cover such a significant number - of peripherals begins to add up quite rapidly. However despite this, - the PLIC as it stands (privspec-v-1.10 chapter 7) actually covers the - requirements quite nicely, as long as it can cope with large numbers - *of* IRQ lines (which it can). Thus the Shakti PLIC Peripheral code - has been modified from its original (which could handle up to XLEN - separate lines) to a hierarchical arrangement that can handle up to - 1024 separate and distinct IRQs - -