CPC700 User’s Manual—Preliminary
8-11
8.4.8 Hi Slave Address Register
This register is not used for 7-bit addressing. To disable 10-bit addressing, this register must be pro-
grammed to zero. To enable 10-bit addressing this register must be programmed to ‘1111 0yyX’ binary,
where:
yy = The high-order two bits of the 10-bit address
X = Don’t care
Thus, in 10-bit address mode, bits 0:6 are used to decode the first address byte that was transmitted on the
IIC bus and bit 7 is in a don’t care state. Note that bit 1 (10/7-bit addressing mode bit) in the control register
is not used to control the decode of 10-bit slave addresses.
8.4.9 Clock Divide Register
This register is used to divide the CPC700 SYS_CLOCK signal to form the base clock that is used for inter-
facing to the IIC bus. This register must be programmed before the mode control register. The IIC state
machines will not be activated until this register is programmed. Locking the state machines in this manner
prevents the IIC hardware from misinterpreting activity on the IIC bus.
Since the base clock is used as the basis for all setup and hold timings on the IIC bus, it is imperative that
the correct value is used. If the wrong value is used, the IIC interface will violate most, if not all, of the IIC
timing specifications. Note that it is possible to run at slower data rates by simply choosing larger values of
N. Table 91 lists the values of N versus the possible frequencies of the CPC700 SYS_CLOCK signal. The
value of N shown is the same regardless of whether standard or fast mode is used.
The clock frequency range selected from Table 91 should cover the frequency of the SYS_CLOCK input to
the CPC700. For example, if the CPC700 SYS_CLOCK=33.33Mhz, the IIC clock divide register should be
programmed to 0x03.
Table 89. Hi Slave Address Register
Register ‘FF6X_000B’ - Hi Slave Address
bit 0
Address bit 0 (MSB)
bit 1
Address bit 1
bit 2
Address bit 2
bit 3
Address bit 3
bit 4
Address bit 4
bit 5
Address bit 5
bit 6
Address bit 6
bit 7
Address bit 7 (LSB - D.C. for 10 bit address))
Table 90. Clock Divide Register
Register ‘FF6X_000C’ - Clock Divide
bit 0
Divide bit 0 (MSB)
bit 1
Divide bit 1
bit 2
Divide bit 2
bit 3
Divide bit 3
bit 4
Divide bit 4
bit 5
Divide bit 5
bit 6
Divide bit 6
bit 7
Divide bit 7(LSB)
Содержание CPC700
Страница 1: ...CPC700 Memory Controller and PCI Bridge User s Manual Version 1 1 Issue Date 3 22 00 Preliminary...
Страница 10: ...Table of Contents x Table of Contents...
Страница 16: ...Tables xvi List of Tables...
Страница 28: ...1 12 CPC700 User s Manual Preliminary...
Страница 72: ...3 36 Processor Interface...
Страница 132: ...4 60 Memory Controller...
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Страница 194: ...6 10 Clock Power Management and Reset...
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Страница 246: ...I 11 2 JTAG...
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