
CHAPTER 17 CLOCKED SERIAL INTERFACE A (CSIA) WITH AUTOMATIC TRANSMIT/RECEIVE FUNCTION
User
’
s Manual U15862EJ3V0UD
510
(6) Automatic data transfer interval specification register n (ADTIn)
This is an 8-bit register used to specify the interval period between 1-byte transfers during automatic data
transfer (ATEn bit of serial operation mode specification register n (CSIMAn) = 1).
Set this register when in master mode (MASTERn bit of CSIMAn register = 1) (setting is unnecessary in slave
mode). Setting in 1-byte transfer mode (ATEn bit of CSIMAn = 0) is also valid. When the interval time
specified by the ADTIn register after the end of 1-byte transfer has elapsed, an interrupt request signal
(INTCSIAn) is output. The number of clocks for the interval can be set to between 0 and 63 clocks.
The specified interval time is the transfer clock (specified by divisor selection register n (BRGCAn)) multiplied
by an integer value.
Example
When ADTIn register = 03H
SCKAn
Interval time of 3 clocks
This register can be set by an 8-bit memory manipulation instruction. However, when the TSFn bit of serial
status register n (CSISn) is 1, rewriting the ADTIn register is prohibited.
ADTIn
After reset: 00H R/W Address: FFFFFD45H, FFFFD55H
7
0
6
0
5
ADTIn5
4
ADTIn4
3
ADTIn3
2
ADTIn2
1
ADTIn1
0
ADTIn0
Remark
n = 0 (V850ES/KF1)
n = 0, 1 (V850ES/KG1, V850ES/KJ1)
(7) CSIAn buffer RAM (CSIAnBm)
This area holds transmit/receive data (up to 32 bytes) in automatic transfer mode in 1-bit units.
The CSIAnBm register can be read/written in 16-bit units only. However, when the higher 8 bits and the
lower 8 bits of the CSIAnBm register are used as the CSIAnBmH register and CSIAnBmL register,
respectively, these registers can be read/written in 8-bit units.
After automatic transfer is started, only data of the number of ADTPn register bytes is transmitted/received in
sequence from the CSIAmB0L register.
Remark
n = 0 (V850ES/KF1)
n = 0, 1 (V850ES/KG1, V850ES/KJ1)
m = 0 to F