
CHAPTER 17 CLOCKED SERIAL INTERFACE A (CSIA) WITH AUTOMATIC TRANSMIT/RECEIVE FUNCTION
User
’
s Manual U15862EJ3V0UD
504
(1) Serial I/O shift register An (SIOAn)
This is an 8-bit register used to store transmit/receive data in 1-byte transfer mode (ATEn bit of serial
operation mode specification register n (CSIMAn) = 0). Writing transmit data to SIOAn starts the transfer. In
addition, after a transfer completion interrupt request signal (INTCSIAn) is output TSFn bit of serial status
register n (CSISn) = 0), data can be received by reading data from SIOAn.
This register can be written or read by an 8-bit memory manipulation instruction. However, writing to the
SIOAn register is prohibited when TSFn bit of serial status register n (CSISn) = 1
RESET input sets this register 00H.
Cautions 1. A transfer operation is started by writing to SIOAn register. Consequently, when
transmission is disabled (TXEn bit of CSIMAn register = 0), write dummy data to the
SIOAn register to start the transfer operation, and then perform a receive operation.
2. Do not write data to SIOAn while the automatic transmit/receive function is operating.
Remark
n = 0 (V850ES/KF1)
n = 0, 1 (V850ES/KG1, V850ES/KJ1)
(2) Automatic data transfer address count register n (ADTCn)
This is a register used to indicate buffer RAM addresses during automatic transfer. When automatic transfer
is stopped, the data position when transfer stopped can be ascertained by reading ADTCn register value.
This register can be set by an 8-bit memory manipulation instruction.
RESET input sets this register to 00H. However, reading from ADTCn register is prohibited when TSFn bit of
serial status register n (CSISn) = 1.
7
ADTCn7
ADTCn
6
ADTCn6
5
ADTCn5
4
ADTCn4
3
ADTCn3
2
ADTCn2
1
ADTCn1
0
ADTCn0
After reset: 00H R Address: FFFFFD47H, FFFFD57H
Remark
n = 0 (V850ES/KF1)
n = 0, 1 (V850ES/KG1, V850ES/KJ1)
17.3 Control Registers
Serial interface CSIAn is controlled by the following six registers.
Serial operation mode specification register n (CSIMAn)
Serial status register n (CSISn)
Serial trigger register n (CSITn)
Divisor selection register n (BRGCAn)
Automatic data transfer address point specification register n (ADTPn)
Automatic data transfer interval specification register n (ADTIn)