User's Manual

GS2101M Architecture GS2101M Low Power WiFi Module Data Sheet
Architecture Description
30 Confidential GS2101M-DS-001270, Release 1.0
2.1.6.2 Real Time Clock Counter
The Real Time Counter features:
– 48-bit length (with absolute duration of 272 years).
– Low-power design.
This counter is automatically reset by power-on-reset.
This counter wraps around (returns to “all-0” once it has reached the highest possible
“all-1” value).
2.1.6.3 RTC I/O
There is one (1) RTC I/O that can be used to control external devices, such as sensors or
wake up the module based on external events or devices.
2.1.7 GS2101M Peripherals
2.1.7.1 SDIO Interface
The SDIO interface is a full / high speed SDIO device (slave). The device supports SPI,
1-bit SD and 4-bit SD bus mode. The SDIO block has an AHB interface, which allows the
CPU to configure the operational registers residing inside the AHB Slave core. The CIS and
CSA area is located inside the internal memory of CPU subsystem. The SDIO Registers
(CCCR and FBR) are programmed by both the SD Host (through the SD Bus) and CPU
(through the AHB bus) via Operational registers. The SDIO block implements the AHB
master to initiate transfers to and from the system memory autonomously.
During the normal initialization and interrogation of the card by the SD Host, the card will
identify itself as an SDIO device. The SD Host software will obtain the card information in
a tuple (linked list) format and determine if that card’s I/O function(s) are acceptable to
activate. If the Card is acceptable, it will be allowed to power up fully and start the I/O
function(s) built into it.
The SDIO interface implements Function 1 in addition to the default Function 0. All
application data transfers are done through the Function 1.
The primary features of this interface are
• Meets SDIO card specification version 2.0.
• Conforms to AHB specification.
• Host clock rate variable between 0 and 40 MHz
• All SD bus modes supported including SPI, 1 and 4 bit SD.
• Allows card to interrupt host in SPI, 1 and 4 bit SD modes.
NOTE: Tested with current test platform up to 33 MHz.