ST7538P STMicroelectronics, ST7538P Datasheet - Page 11

• Manufacturer Part Number: ST7538P
• Description: Telecom Line Management ICs 1/2 Duplex FSK Modem
• Manufacturer: STMicroelectronics
• Type: Single Chipr

Specifications of ST7538P

• Product: Modem Chip
• Supply Voltage (max): 5.25 V, 12.5 V
• Supply Voltage (min): 4.75 V, 7.5 V
• Supply Current: 5 mA, 370 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Package / Case: TQFP-44
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.4 Host Processor Interface
ST7538 exchanges data with the host processor thorough a serial interface.
The data transfer is managed by REG_DATA and
and CLR/T lines.
Four are the ST7538 working modes:
■
■
■
■
REG_DATA and
Table 9. Data and Control register access bits configuration
■
Figure 4. Synchronous and Asynchronous ST7538/Host Controller interfaces
– Asynchronous Mode.
ST7538 allows to interface the Host Controller using a 3 line interface (RXD,TXD &
Data are exchange without any auxiliary Clock reference in an Asynchronous mode without adding any
protocol bits. The host controller has to recover the clock reference in receiving Mode and control the Bit
time in transmission mode. RxD line is forced to a low logic level when no carrier is detected.
Data Transmission
Data Reception
Control Register Read
Control Register Write
Data Reception
Data Transmission
Control Register Read
Control Register Write
Mains Access
ST7538 features two type of communication interfaces:
- Asynchronous
- Synchronous
The selection can be done through the internal Control Register.
RxTx
Host Controller
lines are level sensitive inputs.
Asynchronous
Data Interface
ST7538
RxD
TxD
RxTx
CLR/T
REG_DATA
REG_DATA
RxTx
0
0
1
1
Lines, while data are exchanged using RxD, TxD
Host Controller
Data Interface
Synchronous
D03IN1415
ST7538
RxD
TxD
RxTx
CLR/T
REG_DATA
RxTx
RxTx
0
1
1
0
).
ST7538
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