AT89C5132 Atmel Corporation, AT89C5132 Datasheet - Page 120

• Manufacturer Part Number: AT89C5132
• Manufacturer: Atmel Corporation

Specifications of AT89C5132

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-12C
• Max I/o Pins: 44
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Uart: 1
• Adc Channels: 2
• Adc Resolution (bits): 10
• Adc Speed (ksps): 22.7
• Sram (kbytes): 2.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 3.6
• Timers: 2
• Isp: UART/USB
• Watchdog: Yes

19. Synchronous Peripheral Interface
Figure 19-1. Typical Master SPI Bus Configuration
Figure 19-2. Typical Slave SPI Bus Configuration
120
AT89C5132
AT89C5132
MASTER
The AT89C5132 implement a Synchronous Peripheral Interface with master and slave modes
capability.
Figure 19-1 shows an SPI bus configuration using the AT89C5132 as master connected to slave
peripherals. Figure 19-2 shows an SPI bus configuration using the AT89C5132 as slave of an
other master.
The bus is made of three wires connecting all the devices together:
•
•
•
Each slave peripheral is selected by one Slave Select pin (SS). If there is only one slave, it may
be continuously selected with SS tied to a low level. Otherwise, the AT89C5132 may select each
device by software through port pins (Pn.x). Special care should be taken not to select two
slaves at the same time to avoid bus conflicts.
MISO
MOSI
SCK
SSn
SS1
SS0
P4.0
P4.1
P4.2
Pn.z
Pn.y
Pn.x
Master Output Slave Input (MOSI): it is used to transfer data in series from the master to a
slave. It is driven by the master.
Master Input Slave Output (MISO): it is used to transfer data in series from a slave to the
master. It is driven by the selected slave.
Serial Clock (SCK): it is used to synchronize the data transmission both in and out of the
devices through their MOSI and MISO lines. It is driven by the master for eight clock cycles
which allows to exchange one byte on the serial lines.
MISO
MOSI
SCK
SS
SS
SO
SO
DataFlash 1
Slave 1
SI
SI
SCK
SCK
SS
SS
SO
SO
DataFlash 2
Slave 2
SI
SI
SCK
SCK
MISO MOSI SCK
SS
SS
SO
AT89C5132
Slave n
Controller
SI
LCD
SCK
4173E–USB–09/07