Hardware+Design V1.07
Table Of Contents
- Revision History
- 1 Introduction
- 2 Package Information
- 3 Application Interface Specification
- 4 RF Specification
- 5 Reliability and Operating Characteristics
- 6 Guide for Production
- Appendix
Smart Machine Smart Decision
Figure 19: Null modem
3.3.1 Pin Description
Table 8: Pin description
Pin type Pin name Pin No. I/O Active voltage Default Status
UART_RXD 68 I High/Low Pull-Down
UART_TXD 71 O
High/Low
Pull-Up
UART_RTS 66 O
High/Low
UART_CTS 67 I
High/Low
Pull-Up
UART_DTR 72 I
High/Low
Pull-Up
UART_DCD 70 O
High/Low
UART
UART_RI 69 O
High/Low
More pin information refers to chapter 2.2.
Table 9: Logic level
Parameter Min Max Unit
Logic low input -0.3 0.91 V
Logic high input 1.69 2.9 V
Logic low output 0 0.45 V
Logic high output 2.15 2.6 V
3.3.2 Application Guide
If UART port is used in Null Modem, the pin “RI” can be used as an interrupt signal to HOST. Normally it
will keep high logic level until certain condition such as receiving SMS, voice call (CSD, video) or URC
SIM5320_Hardware Design_V1.07 2012-09-21
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