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| memory_map [2021/09/23 22:48] – [UART] pulkomandy | memory_map [2022/08/19 10:48] – [IO registers] pulkomandy | ||
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| The direction register is 0 for input pins, 1 for output pins. | The direction register is 0 for input pins, 1 for output pins. | ||
| + | ===== Global configuration register ===== | ||
| + | |||
| + | * Bit 0: IOA special functions select | ||
| + | * Bit 1: IOB special functions select | ||
| + | |||
| + | These two bits allow to select one of two special functions for the IOA and IOB registers. Then each pin in that IO register can be switched between normal GPIO and special function using the MASK register. | ||
| + | |||
| + | For IOA, special = 0 selects the TFT display interface, special = 1 selects the STN LCD interface and I2S audio output. | ||
| + | |||
| + | For IOB, only special = 0 is documented and it selects the CSB0, CSB1, CSB2 chip select pins for external memory (further configured by port 3D23) | ||
| + | |||
| + | * Bit 2: IOA Wakeup enable | ||
| + | * Bit 3: IOB Wakeup enable | ||
| + | * Bit 4: IOC Wakeup enable | ||
| + | |||
| + | These bits enable system wakeup from sleep mode from activity on the corresponding IO ports. A typical setup on the V.Smile is to enable wakeup on port B to detect when the ON button is pressed. | ||
| ===== Input pins configuration ===== | ===== Input pins configuration ===== | ||
