h8s-2111b Renesas Electronics Corporation., h8s-2111b Datasheet - Page 431

• Manufacturer Part Number: h8s-2111b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

15.4.2
There are ten kinds of LPC transfer cycle: memory read, memory write, I/O read, I/O write, DMA
read, DMA write, bus master memory read, bus master memory write, bus master I/O read, and
bus master I/O write. Of these, the chip's LPC supports only I/O read and I/O write cycles.
An LPC transfer cycle is started when the LFRAME signal goes low in the bus idle state. If the
LFRAME signal goes low when the bus is not idle, this means that a forced termination (abort) of
the LPC transfer cycle has been requested.
In an I/O read cycle or I/O write cycle, transfer is carried out using LAD3 to LAD0 in the
following order, in synchronization with LCLK. The host can be made to wait by sending back a
value other than B′0000 in the slave's synchronization return cycle, but with the chip's LPC a
value of B′0000 is always returned.
If the received address matches the host address in an LPC register (IDR, ODR, STR, TWR), the
host interface enters the busy state; it returns to the idle state by output of a state count 12
turnaround. Register and flag changes are made at this timing, so in the event of a transfer cycle
forced termination (abort) before state #12, registers and flags are not changed.
State
Count
1
2
3
4
5
6
7
8
9
10
11
12
13
LPC I/O Cycles
Contents
Start
Cycle type/direction Host
Address 1
Address 2
Address 3
Address 4
Turnaround
(recovery)
Turnaround
Synchronization
Data 1
Data 2
Turnaround
(recovery)
Turnaround
I/O Read Cycle
Slave
Drive
Source
Host
Host
Host
Host
Host
Host
None
Slave
Slave
Slave
None
Value
(3 to 0)
0000
0000
Bits 15 to
12
Bits 11 to 8
Bits 7 to 4
Bits 3 to 0
1111
ZZZZ
0000
Bits 3 to 0
Bits 7 to 4
1111
ZZZZ
Contents
Start
Cycle type/direction Host
Address 1
Address 2
Address 3
Address 4
Data 1
Data 2
Turnaround
(recovery)
Turnaround
Synchronization
Turnaround
(recovery)
Turnaround
Rev. 1.00, 05/04, page 397 of 544
I/O Write Cycle
Drive
Source
Host
Host
Host
Host
Host
Host
Host
Host
None
Slave
Slave
None
Value
(3 to 0)
0000
0010
12
Bits 7 to 4
1111
0000
1111
Bits 15 to
Bits 11 to 8
Bits 7 to 4
Bits 3 to 0
Bits 3 to 0
ZZZZ
ZZZZ