User's Manual

Serial TTL Interface Signal Level Pin Assignments

The WHM900¹ is designed for easy connection to any standard serial 3.3V TTL

interface. The connection is made through two 10pin headers.

Serial TTL Interface Signal Level Definition:

PIN Number Name Type Comments

1 P_RXD Input Vih: 2.31V ~ 3.6V

Vil: 0V ~ 0.99V

2 PROG Input Vih: 2.31V ~ 3.6V

Vil: 0V ~ 0.99V

3 MI Output Voh: 2.5V ~3.3V

Vol: 0 ~ 0.4V

4 CTS Output Voh: 2.5V ~3.3V

Vol: 0 ~ 0.4V

5 LIP Output Voh: 2.5V ~3.3V

Vol: 0 ~ 0.4V

6 DTR Input Vih: 2.31V ~ 3.6V

Vil: 0V ~ 0.99V

7 RTS Input Vih: 2.31V ~ 3.6V

Vil: 0V ~ 0.99V

8 TXD Input Vih: 2.31V ~ 3.6V

Vil: 0V ~ 0.99V

9 RXD Output Voh: 2.5V ~3.3V

Vol: 0 V~ 0.4V

10 GND ----

11 P_CLK Input Vih: 2.31V ~ 3.6V

Vil: 0V ~ 0.99V

12 P_TXD Output Voh: 2.5V ~3.3V

Vol: 0V~ 0.4V

13 TXD2 Output Voh: 2.5V ~3.3V

Vol: 0V ~ 0.4V

14 RXD2 Input Vih: 2.31V ~ 3.6V

Vil: 0V ~ 0.99V

15 GND ----

16 RST Input

17 VCC Power Vih: 6.0V

Vil: 3.0V

18 N/C Pin has been

removed

KEYED

19 ---- Not Used

20 ---- Not Used