From 109d9dc7e6362c3cd81f7e37604ab9663ac96848 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sat, 3 Aug 2024 15:24:45 -0400 Subject: soc: pimc: Describe IRQ signalling Signed-off-by: Ian Moffett --- sv/soc/irq/irqchip.md | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'sv/soc/irq/irqchip.md') diff --git a/sv/soc/irq/irqchip.md b/sv/soc/irq/irqchip.md index 9e9b595..e4705a7 100644 --- a/sv/soc/irq/irqchip.md +++ b/sv/soc/irq/irqchip.md @@ -29,3 +29,12 @@ by pulsing IRQACK high for at least 2 ms. As soon as a rising edge of the PIMC CLK signal occurs with IRQACK pulled high, NOTIFY# is pulled high and LINENO[7:0] becomes zero. + +## Signalling + +When a peripheral needs to signal an event, it pulses its IRQ line high for 1 ms which results in +NOTIFY# being pulled low and LINENO[7:0] set to the source line number. After an IRQ has been handled, +it can be acknowledged by pulsing IRQACK high for 2 ms. After an IRQ has been acknowledged, NOTIFY# +is pulled high and LINENO[7:0] is cleared to zero. + +![signals](images/irq.png) -- cgit v1.2.3