AT89C51SND1C-7HTUL Atmel, AT89C51SND1C-7HTUL Datasheet - Page 152

• Manufacturer Part Number: AT89C51SND1C-7HTUL
• Description: IC MCU 64KB FLASH MEM 81-CBGA
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51SND1C-7HTUL

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, IDE/ATAPI, MMC, SPI, UART/USART, USB
• Peripherals: Audio, I²S, MP3, PCM, POR, WDT
• Number Of I /o: 44
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.3 V
• Data Converters: A/D 2x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 81-CBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

19.3.2
19.3.3
19.3.4
152
AT8xC51SND1C
Slave Configuration
Data Exchange
Master Mode with Polling Policy
The SPI operates in slave mode when the MSTR bit in SPCON is cleared and data has been
loaded is SPDAT.
There are 2 possible methods to exchange data in master and slave modes:
•
•
Figure 19-9 shows the initialization phase and the transfer phase flows using the polling method.
Using this flow prevents any overrun error occurrence.
The bit rate is selected according to Table 132. The transfer format depends on the slave
peripheral.
SS may be deasserted between transfers depending also on the slave peripheral.
SPIF flag is cleared when reading SPDAT (SPSTA has been read before by the “end of transfer”
check).
This polling method provides the fastest effective transmission and is well adapted when com-
municating at high speed with other microcontrollers. However, the procedure may then be
interrupted at any time by higher priority tasks.
polling
interrupts
4109L–8051–02/08