Serial Input/Output Library (libsio): Difference between revisions
| Revision as of 02:47, 23 October 2026 RemmyLee (Formats: Sony paragraph voice; HMD, RSD extended files, full BS code book; sprite editor formats) | Revision as of 02:58, 23 October 2026 RemmyLee (Run-time library pages: 20 libraries from the Library Overview and Reference 4.4) | ||
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| + | --- | ||
| + | title: Serial Input/Output Library (libsio) | ||
| + | type: component | ||
| + | summary: Provides standard input and output functions for connecting the PlayStation to a PC. | ||
| + | category: Libraries | ||
| + | info: Library = libsio.lib | ||
| + | info: Header File = libsio.h | ||
| + | --- | ||
| + | |||
| + | ## Overview | ||
| + | |||
| + | The Serial Input/Output Library (libsio) provides standard input and output functions for connecting the PlayStation to a PC, and it supports the output of debug information to the PC.[^o17-3] | ||
| + | |||
| + | A program that uses libsio links with libsio.lib and includes libsio.h.[^o17-3] | ||
| + | |||
| + | ## Serial I/O Driver | ||
| + | |||
| + | libsio consists of the serial I/O driver and the serial I/O BIOS. The driver provides standard input and output through the standard C procedures, so standard I/O can be assigned to the communications port without other code. AddSIO() includes the driver and DelSIO() deletes it. For more complex communication, such as with a PC and a modem, the BIOS is used instead.[^o17-3] | ||
| + | |||
| + | ## Serial I/O BIOS | ||
| + | |||
| + | The serial I/O BIOS provides low-level driver control and information that the standard C functions do not cover. Its interface function is _sio_control(). The libraries normally write debugging data to standard I/O. Data communication with a PC through the driver would therefore receive unexpected data, so such communication uses the BIOS without the driver and with standard I/O in NULL mode. The BIOS also works when the driver is not included.[^o17-3] | ||
| + | |||
| + | _sio_control(cmd, arg, param) issues the SIO commands:[^r16-6] | ||
| + | |||
| + | Table: _sio_control() commands | ||
| + | |||
| + | | cmd | arg | Function | | ||
| + | | --- | --- | --- | | ||
| + | | 0 | 0 | Return the driver status | | ||
| + | | 0 | 1 | Return the control line status | | ||
| + | | 0 | 2 | Return the communications mode | | ||
| + | | 0 | 3 | Return the communications speed in bps | | ||
| + | | 0 | 4 | Read 1 byte | | ||
| + | | 1 | 1 | Set the control line status to param | | ||
| + | | 1 | 2 | Set the communications mode to param | | ||
| + | | 1 | 3 | Set the communications speed to param bps | | ||
| + | | 1 | 4 | Write 1 byte | | ||
| + | | 2 | 0 | Reset the driver | | ||
| + | | 2 | 1 | Clear the error bits of the driver status | | ||
| + | |||
| + | The driver status has the following bits:[^r16-6] | ||
| + | |||
| + | Table: Driver status | ||
| + | |||
| + | | Bit | Symbol | Contents | | ||
| + | | --- | --- | --- | | ||
| + | | 9 | SR_IRQ | Interrupt on | | ||
| + | | 8 | SR_CTS | CTS is on | | ||
| + | | 7 | SR_DSR | DSR is on | | ||
| + | | 5 | SR_FE | Frame error occurs | | ||
| + | | 4 | SR_OE | Overrun error occurs | | ||
| + | | 3 | SR_PERROR | Parity error occurs | | ||
| + | | 2 | SR_TXU | No communications data | | ||
| + | | 1 | SR_RXRDY | Communications data can be read | | ||
| + | | 0 | SR_TXRDY | Communications data can be written | | ||
| + | |||
| + | In the control line status bit 1 is RTS and bit 0 is DTR. In the communications mode bits 7 and 6 give the stop bit length (MR_SB_01, MR_SB_10 and MR_SB_11 for 1, 1.5 and 2 bits). Bit 5 (MR_P_EVEN) selects odd or even parity, bit 4 (MR_PEN) enables parity and bits 3 and 2 give the character length from 5 to 8 bits.[^r16-7] | ||
| + | |||
| + | Sio1Callback() sets a function called on the interrupts enabled by _sio_control(1, 1, param), which are CR_DSRIEN, CR_RXIEN and CR_TXIEN. The callback must clear the interrupt flag with _sio_control(2, 1, 0) or _sio_control(1, 1, CR_ERRRST), since no further SIO interrupt occurs until the flag is cleared.[^r16-5] | ||
| + | |||
| + | ## Functions | ||
| + | |||
| + | In the tables below, Introduced is the run-time library version that added the item.[^reff163] | ||
| + | |||
| + | libsio has the following functions:[^reff163] | ||
| + | |||
| + | Table: libsio functions | ||
| + | |||
| + | | Function | Introduced | Purpose | | ||
| + | | --- | --- | --- | | ||
| + | | `AddSIO` | 3.6 | Initialize SIO driver. | | ||
| + | | `DelSIO` | 3.6 | Delete SIO driver from kernel. | | ||
| + | | `Sio1Callback` | 4.0 | Set SIO interrupt callback function. | | ||
| + | | `_sio_control` | 3.6 | Issue SIO command. | | ||
| + | |||
| + | ## References | ||
| + | |||
| + | [^o17-3]: Sony Computer Entertainment Inc. Run-Time Library Overview. Run-Time Library 4.4. January 1999. Page 17-3. | ||
| + | [^r16-5]: Sony Computer Entertainment Inc. Run-Time Library Reference. Run-Time Library 4.4. January 1999. Page 16-5. | ||
| + | [^r16-6]: Sony Computer Entertainment Inc. Run-Time Library Reference. Run-Time Library 4.4. January 1999. Page 16-6. | ||
| + | [^r16-7]: Sony Computer Entertainment Inc. Run-Time Library Reference. Run-Time Library 4.4. January 1999. Page 16-7. | ||
| + | [^reff163]: Sony Computer Entertainment Inc. Run-Time Library Reference. Run-Time Library 4.4. January 1999. Pages 16-3 to 16-6. | ||