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156
CHAPTER 6 INTERRUPTS
MB90560 series
6.7
6.7.2 Processing time of the extended intelligent I/O service
(EI2OS)
Operation of the extended intelligent I/O service (EI2OS)
The time required for processing the extended intelligent I/O service (EI
2
OS) is varied
according to the following factors:
EI
2
OS status register (ISCS) setting
Address (area) pointed by the I/O register address pointer (IOA)
Address (area) pointed by the buffer address pointer (BAP)
External data bus length for external access
Transfer data length
Because the hardware interrupt is activated when data transfer by EI
2
OS terminates,
the interrupt handling time is needed to be considered.
I
Processing time (one transfer time) of the extended intelligent I/O service (EI
2
OS)
G
When data transfer continues
The EI
2
OS processing time for data transfer continuation is shown in Table 6.7-1 based on the
EI
2
OS status register (ISCS) setting.
Table 6.7-1 Extended intelligent I/O service execution time
Unit:Machine cycle (One machine cycle corresponds to one clock cycle of the machine clock (
φ
).
As shown in Table 6.7-2, compensation is necessary depending on the EI
2
OS execution
condition.
Table 6.7-2 Data transfer compensation value for EI
2
OS execution time
B:Byte data transfer
8:External bus using the 8-bit word transfer
Even:Even-numbered address word transfer
Odd:Odd-numbered address word transfer
EI
2
OS termination control bit (SE) setting
Terminates due to
termination request
from the peripheral
Ignores termination
request from the
peripheral
IOA update/fixed selection bit (IF) setting
Fixed
Update
Fixed
Update
BAP address update/fixed selection bit
(BF) setting
Fixed
Update
32
34
34
36
33
35
35
37
I/O register address pointer
Internal access
External access
B/Even
Odd
B/Even
8/Odd
Buffer address
pointer
Internal access
B/Even
Odd
B/Even
8/Odd
0
+2
+4
+3
+6
+1
+3
+2
+5
+4
+6
+5
+8
+2
+1
+4
External access