Reduced Serial Bus

The RSBTM is a push-pull two wire bus developed by Allwinner Technology that supports multiple devices. It supports speeds up to 20 MHz.

= Features =
 * Supports industry-standard AMBA Peripheral Bus (APB) and is fully compliant with the AMBA Specification, Revision 2.0
 * Supports speeds up to 20 MHz
 * Supports Push-Pull bus
 * Supports Host mode
 * Supports multiple devices
 * Supports programmable output delay of CD signal
 * Supports parity check for address and data transmission

= Registers = This list was created from Allwinner code.

CCR
This register controls the RSB bus clock (SCK) speed.

INTE
This register masks/unmasks interrupt events.

STATUS
This register shows interrupt and transfer status. Write 1 to the corresponding bit to clear each interrupt.

LCR
This register can seemingly be used to bit bang the bus.

PMCR
Init sequence related

CMD
List of command codes

SADDR
= Hardware Addresses = RSB has hardware addresses and runtime addresses. Runtime addresses are configured at initialization time, and are used to talk to the slave devices. Hardware addresses are used to identify and configure runtime addresses. The configured runtime addresses are not queryable.

Allwinner sources use a static mapping of hardware and runtime addresses.