25
PC8240
2149A–HIREL–05/02
Notes: 1. Units for these specifications are in SDRAM_CLK units.
2. The actual values depend on the setting of the Digital Filter Frequency Sampling Rate (DFFSR) bits in the Frequency
Divider Register I2CFDR. Therefore, the noted timings in the above table are all relative to qualified signals. The qualified
SCL and SDA are delayed signals from what is seen in real time on the two-wire interface bus. The qualified SCL, SDA
signals are delayed by the SDRAM_CLK clock times DFFSR times 2 plus 1 SDRAM_CLK clock. The resulting delay value is
added to the value in the table (where this note is referenced). See Figure 16 on page 27.
3. Timing is relative to the Sampling Clock (not SCL).
4. FDR[x] refers to the Frequency Divider Register I2CFDR bit x.
5. Input clock low and high periods in combination with the FDR value in the Frequency Divider Register (I2CFDR) determine
the maximum two-wire interface input frequency. See Figure 16 on page 27.
Table 14 provides the two-wire interface Frequency Divider Register (I2CFDR) informa-
tion for the PC8240.
At recommended operating conditions (see Table 3 on page 8) with GVdd = 3.3V ± 5%
and LVdd = 3.3V ± 5%
6 Clock high period
(Time needed to either receive a data bit or
generate a START or STOP.)
5.0 – CLKs (1)(2)(5)
7 Data setup time 3.0 – ns (3)
8 Start condition setup time (for repeated start
condition only) 4.0 – CLKs (1)(2)
9 Stop condition setup time 4.0 – CLKs (1)(2)
Table 13. Two-wire Interface Input AC Timing Specifications (Continued)
Num Characteristics Min Max Unit Notes
Table 14. PC8240 Maximum Two-wire Interface Input Frequency
FDR Hex(2) Divider (Dec)(2)
Max Two-wire Interface Input Frequency(1)
SDRAM_CLK
at 25 MHz SDRAM_CLK
at 33 MHz SDRAM_CLK
at 50 MHz SDRAM_CLK
at 100 MHz
20, 21 160, 192 862 1.13 MHz 1.72 MHz 3.44 MHz
22, 23, 24, 25 224, 256, 320, 384 555 733 1.11 MHz 2.22 MHz
0, 1 288, 320 409 540 819 1.63 MHz
2, 3, 26, 27, 28, 29 384, 448, 480, 512, 640,
768 324 428 649 1.29 MHz
4, 5 576, 640 229 302 458 917
6, 7, 2A, 2B, 2C, 2D 768, 896, 960, 1024, 1280,
1536 177 234 354 709
8, 9 1152, 1280 121 160 243 487
A, B, 2E, 2F, 30, 31 1536, 1792, 1920, 2048,
2560, 3072 92 122 185 371
C, D 2304, 2560 62 83 125 251
E, F, 32, 33, 34, 35 3072, 3584, 3840, 4096,
5120, 6144 47 62 95 190
10, 11 4608, 5120 32 42 64 128
12, 13, 36, 37, 38, 39 6144, 7168, 7680, 8192,
10240, 12288 24 31 48 96