SH7261 Datasheet, PDF (910/1348 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7260 Series

Section 20 IEBus^TM Controller (IEB) [R5S72612] [R5S72613]
(2) Communications Mode
The IEBus has three communications modes with different transfer speeds. Table 20.2 shows the
transfer speed in each communications mode and the maximum number of transfer bytes in one
communications frame.
Table 20.2 Transfer Speed and Maximum Number of Transfer Bytes in Each
Communications Mode
Maximum Number
Communications of Transfer Bytes
Mode
(bytes/frame)
Effective Transfer Speed*¹ (kbps)
IEBφ*² = 6, 12, 18, 24, IEBφ*² = 6.29, 12.58, 18.87,
30, 36*³ MHz
25.16, 31.45, 37.74*³ MHz
0
16
About 3.9
About 4.1
1
32
About 17
About 18
2
128
About 26
About 27
Notes:
Each unit connected to the IEBus should select a communications mode prior to
performing communications. Note that correct communications is not guaranteed if the
master and slave units do not adopt the same communications mode.
In the case of communications between a unit with φ = 6 MHz and a unit with φ = 6.29
MHz, correct communications are not possible even if the same communications mode
is adopted. Communications must be done with the same oscillation frequency.
1. Effective transfer speed when the maximum number of transfer bytes is transmitted.
2. Peripheral clock (Pφ), or clocks for AUDIO_X1 and AUDIO_X2
3. Oscillation frequency when this LSI is used
(3) Communications Address
In the IEBus, a specific 12-bit communications address is allocated to each individual unit. A
communications address is configured as follows.
• Upper four bits: group number (number identifying a group to which the unit belongs)
• Lower eight bits: unit number (number identifying individual units in a group)
Rev. 2.00 Sep. 07, 2007 Page 878 of 1312
REJ09B0320-0200