CYW20704
3.8 Collaborative Coexistence
The CYW20704 provides extensions and collaborative coexistence to the standard Bluetooth AFH for direct communication with
WLAN devices. Collaborative coexistence enables WLAN and Bluetooth to operate simultaneously in a single device. The device
supports industry-standard coexistence signaling, including 802.15.2, and supports Cypress and third-party WLAN solutions.
3.9 Global Coexistence Interface
The CYW20704 supports the proprietary Cypress Global Coexistence Interface (GCI) which is a 2-wire interface.
The following key features are associated with the interface:
■ Enhanced coexistence data can be exchanged over GCI_SECI_IN and GCI_SECI_OUT a two-wire interface, one serial input
(GCI_SECI_IN), and one serial output (GCI_SECI_OUT). The pad configuration registers must be programmed to choose the digital
I/O pins that serve the GCI_SECI_IN and GCI_SECI_OUT function.
■ It supports generic UART communication between WLAN and Bluetooth devices.
■ To conserve power, it is disabled when inactive.
■ It supports automatic resynchronizaton upon waking from sleep mode.
■ It supports a baud rate of up to 4 Mbps.
3.9.1 SECI I/O
The CYW20704 devices have dedicated GCI_SECI_IN and GCI_SECI_OUT pins. The two pin functions can be mapped to any of
the Cypress Global Co-existence Interface (GCI) GPIO. Pin function mapping is controlled by the configuration file that is stored in
either NVRAM or downloaded directly into on-chip RAM from the host.
3.10 Recommended BT Coexistence Interface Assignments
The following tables show the recommended BT coexistence interface assignments.
Table 3. BT GCI Two-Wire Coexistence
Coexistence Signal Name
BT_SECI_IN
BT_SECI_OUT
Signal Assignment
Signal Assignment
Pin Number
Pin Number
GPIO_6
GPIO_7
B6
C6
Table 4. BT GCI Three-Wire Coexistence
Coexistence Signal Name
BTCX_WL_ACTIVE
BTCX_BT_ACTIVE
BTCX_PRI_STATUS
PCM_IN
C7
C8
B7
PCM_SYNC
PCM_CLK
Table 5. BT GCI Four-Wire Coexistence
Coexistence Signal Name
Signal Assignment
Pin Number
BTCX_WL_ACTIVE
BTCX_BT_ACTIVE
BTCX_PRI_STATUS
BTCX_STATUS2
PCM_IN
C7
C8
B7
A8
PCM_SYNC
PCM_CLK
PCM_OUT
Document Number: 002-14786 Rev. *E
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