Uart Interface Compatibility Design; Detailed Interface Differences - Huawei MU509 Hardware Migration Manual

HUAWEI 30 mm × 30 mm LGA Module
Hardware Migration Guide
Figure 2-21 Circuit of the JTAG interface

2.9 UART Interface Compatibility Design

2.9.1 Detailed Interface Differences

Please note that the different signal level of UART between MU509/MC509 and
MU609/ME209u-526/ME909u/MU709/ME909s. The signal level of MU509/MC509 is
CMOS 2.6 V and MU609/MU709/ME209u-526/ME909u/ME909s is CMOS 1.8 V.
Therefore, you must consider compatibility during circuit designing.
ME209u-526 and ME909u only support two 4-wire line UARTs and one 2-wire UART
(only for debugging), and do not support 8-wire line UART.
For ME909s, the UART cannot wake up the module from the sleep status, and you
can pull up the WAKEUP_IN signal for 1s instead.
Issue 08 (2016-12-12)
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