FreeCalypso > hg > freecalypso-reveng
view gtm900/interface-signals @ 370:844f884e0171
pirelli/vibrator-ctrl: additional observations
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sat, 29 May 2021 18:23:34 +0000 |
parents | c06cac606af3 |
children |
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UART interfaces =============== Both Calypso UARTs are brought out on the GTM900 module interface as follows: Pin Name in manual Connected Calypso ball 11 RXD2 TX_IRDA 12 TXD2 RX_IRDA ------------------------------- 16 UART_DSR GPIO1 17 UART_RI GPIO0 18 UART_RXD TX_MODEM 19 UART_TXD RX_MODEM 20 UART_CTS RTS_MODEM 21 UART_RTS CTS_MODEM 22 UART_DTR GPIO3 23 UART_DCD GPIO2 The interface signal names in Huawei's manual are given from the host's perspective (classic DTE-to-DCE paradigm), thus they are the opposite of the connected Calypso signal names. For the MODEM UART a complete 8-signal interface with full modem control is defined, but the Calypso only provides TxD & RxD, RTS & CTS, thus the other 4 modem control signals are GPIOs. The signals which are defined as DTR and DCD from the host's perspective are connected to GPIOs 3 and 2, respectively, just like on TI's C-Sample and D-Sample boards, whereas the choices of GPIOs for DSR and RI are Huawei's own arbitrary picks, as TI's development boards did not provide these signals. Power control signals ===================== Interface pin 13 (called VDD in the manual) appears to be connected to the V-IO rail inside. Interface pin 15 (PWON) is connected directly to Iota PWON as expected. Interface pin 31 (called RST in the manual) appears to be connected to Iota nTESTRESET through the same transistor circuit as on TI's development boards, i.e., the signal brought out on the module interface is not raw nTESTRESET, but what we call XDS_RESET, originally meant to be driven by TI's XDS510 and XDS560 "emulator" pods. Other signals ============= Interface pin 14 (called ADC in the manual) is connected to Iota ADIN1. Interface pin 32 (called LPG in the manual) is indeed connected to Calypso ball DSR_MODEM/LPG, which Huawei's firmware configures to be the LPG output.