Specifications

GOODOCOM Technologies Confidential GOC-BA440 Specification
GOODOCOM Technologies Confidential 14
Notes:
1. VBAT should not rise 10%–90% faster than 40 microseconds.
2. VBAT should be up before or at the same time as VDDIO. VDDIO should NOT be present first or be held
high before VBAT is high.
8.5 Power On Sequence for WLAN OFF and BT On
Figure 9: WLAN = OFF, Bluetooth = ON
Notes:
1. VBAT should not rise 10%–90% faster than 40 microseconds.
2. VBAT should be up before or at the same time as VDDIO. VDDIO should NOT be present first or be held
high before VBAT is high.
9. UART Interface
The UART is a standard 4-wire interface (RX, TX, RTS, and CTS) with adjustable baud rates from 9600
bps to 4.0 Mbps. The interface features an automatic baud rate detection capability that returns a baud rate
selection. Alternatively, the baud rate may be selected through a vendor-specific UART HCI command.
UART has a 1040-byte receive FIFO and a 1040-byte transmit FIFO to support EDR. Access to the
FIFOs is conducted through the AHB interface through either DMA or the CPU. The UART supports the
Bluetooth 4.1 UART HCI specification: H4, a custom Extended H4, and H5. The default baud rate is 115.2
Kbaud.
The UART supports the 3-wire H5 UART transport, as described in the Bluetooth specification (Three-
wire UART Transport Layer). Compared to H4, the H5 UART transport reduces the number of signal lines
required by eliminating the CTS and RTS signals.
The GOC-BA440 UART can perform XON/XOFF flow control and includes hardware support for the
Serial Line Input Protocol (SLIP). It can also perform wake-on activity. For example, activity on the RX or
CTS inputs can wake the chip from a sleep state.
Normally, the UART baud rate is set by a configuration record downloaded after device reset, or by
automatic baud rate detection, and the host does not need to adjust the baud rate. Support for changing the
baud rate during normal HCI UART operation is included through a vendor-specific command that allows
the host to adjust the contents of the baud rate registers. The GOC-BA440 UARTs operate correctly with the
host UART as long as the combined baud rate error of the two devices is within ±2%.