PTA Configurations for PTA Main (SiWG917)#

The SiWG917 PTA feature can be configured by enabling BIT[21] (SL_SI91X_PTA_3WIRE_EN) in the config feature bit-map of the Operation Mode command. There are three different configurations, which can be selected by enabling or disabling Bit [23:22] (SL_SI91X_PTA_3WIRE_CONFIG_SEL(config_sel)). Each configuration modifies the behavior of how the GRANT signal is asserted in response to the REQUEST and PRIORITY signals. The following tables define these configurations:


BIT 23	BIT 22	Configuration
0	0	Reserved
0	1	Configuration 1
1	0	Configuration 2
1	1	Configuration 3

Configuration	Description
Configuration 1	The PTA Main will aggressively assert the GRANT signal if the REQUEST signal is asserted, regardless of whether the PRIORITY signal is asserted or not. This means that any ongoing Wi‑Fi transmission will be aborted, and GRANT will be provided to the PTA Secondary.
Configuration 2	The PTA Main will aggressively assert the GRANT signal if the REQUEST signal is asserted, regardless of whether the PRIORITY signal is asserted or not, with one exception. If there is an ongoing ACK/Block ACK transmission in response to a Wi‑Fi reception, the PTA Main will grant access only if both the PRIORITY and REQUEST signals are asserted.
Configuration 3	If there is an ongoing Wi‑Fi transmission (including ACK/Block ACK), the PTA Main will not assert the GRANT signal in response to an asserted REQUEST. However, if both PRIORITY and REQUEST signals are asserted, the PTA Main will assert the GRANT signal.

PTA Main Application Configuration#

SiWG917 needs to use the throughput application to show the throughput values. Refer to the throughput application for more details.
The BIT (21) (SL_SI91X_PTA_3WIRE_EN) of "config_feature_bit_map" is used to enable the PTA 3-wire feature. BIT (22) and BIT (23) (SL_SI91X_PTA_3WIRE_CONFIG_SEL(config_sel)) are used to select the required PTA configurations. This bitmap selection is available in the "app.c" file under the “sl_wifi_device_configuration_t” structure section. The "config_feature_bit_map" gets enabled when BIT (31) is set to '1' in both "tcp_ip_feature_bit_map" and "ext_tcp_ip_feature_bit_map".
Below is the reference to enable, configure and use the PTA 3-wire feature followed by available different configurations:
```
#define SL_SI91X_PTA_3WIRE_EN BIT(21)#define SL_SI91X_PTA_3WIRE_EN BIT(21)
```
Configurability options for config selection among 1, 2 & 3. Where BIT[22] - BIT[23] are used to set NUM_CONN_EVENTS(the number of BLE connection events.To know more about NUM_CONN_EVENTS please visit the link.
In below table, '0' is kept reserved for future. PTA 3-wire used at DUT as GPIO_7 (Grant pin driven by DUT), ULP_GPIO_1(Request i/p pin for DUT) and ULP_GPIO_6(PRIORITY i/p pin for DUT).
Mode
BIT[23]
BIT[22]
Reserved
0
0
config1
0
1
config2
1
0
config3
1
1
PTA 3-wire configuration needs to be updated in the "app.c" file as mentioned below to configure the config1, config2 & config3:
```
.config_feature_bit_map = 
SL_SI91X_PTA_3WIRE_EN | 
SL_SI91X_PTA_3WIRE_CONFIG_SEL(config_sel).config_feature_bit_map = 
SL_SI91X_PTA_3WIRE_EN | 
SL_SI91X_PTA_3WIRE_CONFIG_SEL(config_sel)
```
whereas "config_sel" will be 1, 2, and 3 based on the "config" mode that user wants to use.

Mode	BIT[23]	BIT[22]
Reserved	0	0
config1	0	1
config2	1	0
config3	1	1

Note: It is advised to run PTA Main i.e., throughput first and then execute commands for PTA Secondary.