DF2148BTE20 Renesas Electronics America, DF2148BTE20 Datasheet - Page 443

• Manufacturer Part Number: DF2148BTE20
• Description: IC H8S MCU FLASH 128K 100-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2100r

Specifications of DF2148BTE20

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: I²C, IrDA, SCI, X-Bus
• Peripherals: PWM, WDT
• Number Of I /o: 74
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: HD64F2148BTE20; HD64F2148BTE20

Section 15 Serial Communication Interface (SCI and IrDA)
15.5
Multiprocessor Communication Function
Use of the multiprocessor communication function enables data transfer to be performed among a
number of processors sharing communication lines by means of asynchronous serial
communication using the multiprocessor format, in which a multiprocessor bit is added to the
transfer data. When multiprocessor communication is carried out, each receiving station is
addressed by a unique ID code. The serial communication cycle consists of two component cycles:
an ID transmission cycle which specifies the receiving station, and a data transmission cycle for
the specified receiving station. The multiprocessor bit is used to differentiate between the ID
transmission cycle and the data transmission cycle. If the multiprocessor bit is 1, the cycle is an ID
transmission cycle, and if the multiprocessor bit is 0, the cycle is a data transmission cycle. Figure
15.10 shows an example of inter-processor communication using the multiprocessor format. The
transmitting station first sends the ID code of the receiving station with which it wants to perform
serial communication as data with a 1 multiprocessor bit added. It then sends transmit data as data
with a 0 multiprocessor bit added. The receiving station skips data until data with a 1
multiprocessor bit is sent. When data with a 1 multiprocessor bit is received, the receiving station
compares that data with its own ID. The station whose ID matches then receives the data sent next.
Stations whose ID does not match continue to skip data until data with a 1 multiprocessor bit is
again received.
The SCI uses the MPIE bit in SCR to implement this function. When the MPIE bit is set to 1,
transfer of receive data from RSR to RDR, error flag detection, and setting the SSR status flags,
RDRF, FER, and ORER in SSR to 1 are prohibited until data with a 1 multiprocessor bit is
received. On reception of a receive character with a 1 multiprocessor bit, the MPB bit in SSR is set
to 1 and the MPIE bit is automatically cleared, thus normal reception is resumed. If the RIE bit in
SCR is set to 1 at this time, an RXI interrupt is generated.
When the multiprocessor format is selected, the parity bit setting is invalid. All other bit settings
are the same as those in normal asynchronous mode. The clock used for multiprocessor
communication is the same as that in normal asynchronous mode.
Rev. 3.00 Mar 21, 2006 page 387 of 788
REJ09B0300-0300